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Preprint ARTICLE | doi:10.20944/preprints202003.0227.v1

One Observer Universe: A Geometric Interpretation of Speed of Light and Mass

Ahmed Farag Ali

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: general relativity; gravity; black holes; ADM formalism

Online: 13 March 2020 (03:28:37 CET)

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Preprint ARTICLE | doi:10.20944/preprints201607.0051.v1

Search for QPOs in the Light Curve of the Blazar OJ287: Preliminary Results from 2015/16 Observing Campaign

S. Zola, M. Valtonen, G. Bhatta, A. Goyal, B. Debski, A. Baran, J. Krzesinski, M. Siwak, S. Ciprini, A. Gopakumar, H. Jermak, K. Nilsson, D. Reichart, K. Matsumoto, K. Sadakane, K. Gazeas, M. Kidger, V. Piirola, F. Alicavus, K.S. Baliyan, A. Berdyugin, D. Boyd, M. Campas Torrent, F. Campos, J. Carrillo Gomez, D.B. Caton, V. Chavushyan, J. Dalessio, D. Dimitrov, M. Drozdz, A. Erdem, A. Escartin Perez, V. Fallah Ramazani, A.V. Filippenko, F. Garcia, F. Gomez Pinilla, M. Gopinathan, J.B. Haislip, J. Harmanen, G. Hurst, K.M. Ivarsen, M. Jelinek, A. Joshi, M. Kagitani, N. Kaur, N. Karaman, W.C. Keel, A.P. LaCluyze, B.C. Lee, E. Lindfors, J. Lozano De Haro, J.P. Moore, R. Naves Nogues, A.W. Neely, R.H. Nelson, W. Ogloza, S. Okano, J.C. Pandey, M. Perri, P. Pihajoki, G. Poyner, J. Provencal, T. Pursimo, A. Raj, R. Reinthal, S. Sadegi, T. Sakanoi, J.-L. Salto Gonzales, T. Schweyer, F.C. Soldan Alfaro, E. Sonbas, I. Steele, J.T. Stocke, J. Strobl, L.O. Takalo, T. Tomov, L. Tremosa Espasa, J.R. Valdes, J. Valero Perez, F. Verrecchia, J.R. Webb, M. Yoneda, M. Zejmo, W. Zheng, J. Telting, J. Saario, T. Reynolds, A. Kvammen, E. Gafton, R. Karjalainen, P. Blay

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies: active; BL Lacertae objects: individual (OJ 287); super massive black holes

Online: 18 July 2016 (10:46:26 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0026.v1

Microscopic Processes In Global Relativistic Jets Containing Helical Magnetic Fields

Kenichi Nishikawa, Yosuke Mizuno, Jacek Niemiec, Oleh Kobzar, Martin Pohl, Jose Gomez, Ioana Dutan, Asaf Pe’er, Jacob Frederiksen, Aake Nordlund, Athina Meli, Helene Sol, Phil Hardee, Dieter Hartmann

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: relativistic jets; particle-in-cell simulations; global jets; helical magnetic fields; kinetic instabilities; kink instability

Online: 13 July 2016 (05:37:49 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0060.v1

The RadioAstron dedicated DiFX distribution

Gabriele Bruni, James M. Anderson, Walter Alef, Helge Rottmann, Andrei P. Lobanov, J. Anton Zensus

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: VLBI; Space-VLBI; Correlation; RadioAstron; AGN

Online: 19 July 2016 (04:54:57 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0038.v1

Exploring The Magnetic Field Configuration Close To The Central Engines Using GMVA

Bindu Rani, Thomas Krichbaum, J. Hodgson, Shoko Koyama, Anton J. Zensus, Alan Marscher, Svetlana Jorstad, Lars Fuhramnn

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: active galaxies; BL Lacertae object: BL Lac; jets; GMVA: high-resolution VLBI; magnetic field; polarization

Online: 15 July 2016 (10:06:48 CEST)

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Preprint REVIEW | doi:10.20944/preprints201609.0096.v2

Quantum Cosmology vs. Observational Cosmology (A Simple, Curious and Advanced Approach)

U. V. S. Seshavatharam, S. Lakshminarayana

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: big bang; planck scale Hubble parameter; quantum cosmology; Mach’s principle; holographic principle; observational cosmology; super luminal expansion speed; super luminal rotation speed; dark energy; cosmic rotational kinetic energy; cosmic microwave back

Online: 8 October 2016 (10:26:06 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0044.v1

MWL Picture Of The Blazar S5 0716+714 During Its Brightest Outburst

Marina Manganaro, Giovanna Pedaletti, Marlene Doert, Denis Bastieri, Vandad Fallah Ramazani, Dario Gasparrini, Elina Lindfors, Benoit Lott, Mireia Nievas, Bindu Rani, Emmanouil Angelakis, George Borman, Mark Gurwell, Talvikki Hovatta, Ryosuke Itoh, Svetlana Jorstad, Alex Kraus, Thomas P Krichbaum, Paul Kuin, Anne Lahteenmaki, Valeri Larionov, Amy Yarleen Lien, Ioannis Myserlis, David J Thompson, Merja Tornikoski, J Anton Zensus

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: BL-Lacertae objects: individual: S5 0716+714; Galaxies:active; gamma-rays: galaxies

Online: 18 July 2016 (06:02:42 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201608.0002.v1

Results of Long-Duration Simulation of Distant Retrograde Orbits

Gary Turner

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Distant Retrograde Orbit; DRO; orbits–stability; radiation pressure; orbits–resonance; dynamics

Online: 1 August 2016 (09:00:06 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201611.0080.v1

Dark Matter as a Metric Perturbation

W. M. Stuckey, Timothy McDevitt, A. K. Sten, Michael Silberstein

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: dark matter; THINGS; MOND; metric skew-tensor gravity; scalar-tensor-vector gravity; CMB angular power spectrum

Online: 16 November 2016 (09:39:24 CET)

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Preprint REVIEW | doi:10.20944/preprints201702.0002.v1

Tests and Problems of the Standard Model in Cosmology

Martin Lopez-Corredoira

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Cosmology; Observational cosmology; Origin, formation, and abundances of the elements; dark matter; dark energy; superclusters; large-scale structure of the Universe

Online: 1 February 2017 (16:06:52 CET)

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Preprint ARTICLE | doi:10.20944/preprints201607.0036.v1

The Classifications and Some Correlations for Fermi Blazars

Junhui Fan, Y Liu, J.H. Yang, C Lin, J.M. Hao

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies: active; galaxies: jets; galaxies: nuclei

Online: 15 July 2016 (09:37:39 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0023.v1

Observing---and Imaging---Active Galactic Nuclei with the Event Horizon Telescope

Vincent Fish, Kazunori Akiyama, Katherine Bouman, Andrew Chael, Michael Johnson, Sheperd Doeleman, Lindy Blackburn, John Wardle, William Freeman

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies: jets---Galaxy: center---techniques: high angular resolution---techniques: image processing---techniques: interferometric

Online: 12 July 2016 (09:41:39 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0034.v1

Flaring γ-ray emission from high redshift blazars

Monica Orienti, Filippo D'Ammando, Marcello Giroletti, Justin Finke, Daniele Dallacasa

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies: active; gamma-rays: general; radiation mechanisms: non-thermal

Online: 15 July 2016 (04:40:29 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201710.0113.v1

Entropy and Geometric Objects

Georg J. Schmitz

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: gradient-entropy; contrast; phase-field models; diffuse interfaces; entropy of geometric objects; Bekenstein-Hawking entropy; Heaviside function; Dirac function; 3D Delta function

Online: 17 October 2017 (10:48:36 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0025.v1

Broad Band Observations Of Gravitationally Lensed Blazar QSO B0218+357 During A Gamma-Ray Outburst

Julian Sitarek, Josefa Becerra González, Sara Buson, Dijana Dominis Prester, Marina Manganaro, Daniel Mazin, Kari Nilsson, Mireia Nievas, Antonio Stamerra, Fabrizio Tavecchio, Ievgen Vovk

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Gamma rays: galaxies; Gravitational lensing: strong; Galaxies: jets; Radiation mechanisms: non-thermal; Galaxies: individual: QSO B0218+357

Online: 13 July 2016 (05:36:15 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0040.v1

A panchromatic view of relativistic jets in narrow-line Seyfert 1 galaxies

Filippo D'Ammando, Monica Orienti, Justin Finke, Josefin Larsson, Marcello Giroletti, Claudia M. Raiteri

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies: nuclei; galaxies: jets; galaxies: Seyfert; gamma-rays: general

Online: 15 July 2016 (11:29:08 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0008.v1

Spectral and Polarization Signatures of Relativistic Shocks in Blazars

Markus Boettcher

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: active galaxies; blazars; jets; polarization; shock acceleration

Online: 8 July 2016 (03:03:04 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201607.0058.v1

The thermodynamics of collapsars

Trevor W. Marshall

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Gravitational collapse; Oppenheimer-Snyder; horizonless solutions; neutron stars

Online: 19 July 2016 (04:53:26 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201705.0164.v4

The Impact of the Cosmological Constant on the Newtonian Gravity

Engel Roza

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Cosmological Constant; MOND; dark matter; antigravity

Online: 31 August 2018 (05:24:08 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201805.0048.v2

A Simplified View on Entropic Gravity

Engel Roza

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: entropic gravity; MOND; dark matter

Online: 8 June 2018 (12:40:57 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201608.0229.v1

On the Non-Thermal Energy Content of Cosmic Structures

Franco Vazza, Denis Wittor, Marcus Brueggen, Claudio Gheller

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Galaxy clusters; cosmic rays; magnetic fields; turbulence

Online: 30 August 2016 (08:53:32 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201703.0136.v1

A Combined Entropy/Phase-Field Approach to Gravity

Georg J. Schmitz

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: entropic gravity; Lagrange formalism; phase-field models; gradient-entropy; constraints; maximum entropy principle; curvature of space; conservation laws; Modified Newtonian Dynamics; MOND

Online: 17 March 2017 (05:16:12 CET)

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Preprint ARTICLE | doi:10.20944/preprints201607.0032.v1

The radio/gamma-ray connection from 120 MHz to 230 GHz

Marcello Giroletti, Filippo D'Ammando, Monica Orienti, Rocco Lico

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: BL Lacertae objects: general, catalogues, gamma rays: galaxies, quasars: general, radiation mechanisms: non-thermal, radio continuum: galaxies

Online: 14 July 2016 (12:11:50 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201703.0115.v1

Towards a More Well-Founded Cosmology

Hartmut Traunmüller

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: foundations of science; cosmology: observations; cosmology: theory; galaxies: kinematics and dynamics; inertia; MoND

Online: 16 March 2017 (09:31:27 CET)

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Preprint ARTICLE | doi:10.20944/preprints201612.0057.v1

Using the Outskirts of Galaxy Clusters to Determine their Mass Accretion Rate

Cristiano De Boni

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies; clusters; general; methods N-body simulations; cosmology; theory

Online: 9 December 2016 (16:38:17 CET)

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Preprint ARTICLE | doi:10.20944/preprints201703.0009.v1

Gaussian Processes for Blazar Variability Studies

Vassilis Karamanavis

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: active galaxies; blazars; jets; radio continuum; gamma-rays; time-series analysis; Bayesian modelling; Gaussian processes

Online: 1 March 2017 (12:56:13 CET)

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Preprint REVIEW | doi:10.20944/preprints202110.0402.v1

Jim Henry, Mesut Yurukcu, George Nnanna

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Universe; galaxies; Milky Way Galaxy; spiral galaxies; hurricanes; pattern.

Online: 27 October 2021 (11:49:50 CEST)

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Preprint ARTICLE | doi:10.3390/sci2010010

Data Fusion of Scanned Black and White Aerial Photographs with Multispectral Satellite Images

Dimitris Kaimaris, Petros Patias, Giorgos Mallinis, Charalampos Georgiadis

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: black and white aerial photographs; multispectral satellite images; data fusion; correlation tables; classification

Online: 13 March 2020 (00:00:00 CET)

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Preprint ARTICLE | doi:10.20944/preprints201908.0050.v1

Gravitational Waves in Newton’s Gravitation and Criticism of Gravitational Waves Resulting from the General Theory of Relativity (LIGO)

Roman Szostek, Paweł Góralski, Kamil Szostek

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: gravitational wave; Newton’s gravitation; LIGO interferometer

Online: 5 August 2019 (05:24:18 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201801.0251.v2

“All That Matter ... in One Big Bang ...,” & Other Cosmological Singularities

Emilio Elizalde

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: The Big Bang concept; history of modern cosmology; singularity theorems; cosmological singularities in modified gravity models

Online: 8 February 2018 (08:54:20 CET)

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Working Paper ARTICLE

Solution to the Advance of the Perihelion of Mercury in Newtonian Theory

Christian Corda

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: perihelion of Mercury; Newtonian theory; precession

Online: 19 June 2020 (08:43:00 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201706.0051.v1

Beyond ɅCDM: A Viable Alternative?

Paul Gough

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: cosmology; dark energy; dark matter; cosmological constant problem

Online: 12 June 2017 (06:16:52 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201706.0019.v2

Quantum Space and the Evolution of the Dark Universe

Carlos A. Melendres

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: quantum space; expansion of the universe; dark energy; thermodynamics; dark matter; plasma; recombination; vacuum energy; Cosmological Constant; Quintessence; spaceons

Online: 18 August 2017 (04:51:40 CEST)

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We present a model of space that considers it to be a quantized dynamical entity which is a component of the universe along with matter and radiation. The theory is used together with thermodynamic data to provide a new view of cosmic evolution and an insight into the nature of dark energy and dark matter. Space is made up of energy quanta. The universe started from an atomic size volume at very high temperature and pressure near the Planck epoch. Upon expansion and cooling, phase transitions occurred resulting in the formation of radiation, fundamental particles, and matter. These nucleate and grow into stars, galaxies, and clusters. From a phase diagram of cosmic composition, we obtained a correlation between dark energy and the energy of space. Using the Friedmann equations, data from WMAP studies of the composition of the universe at 3.0 x 10⁵ (a=5.25 x 10^-2) years and at present (a=1), are well fitted by our model with an equation of state parameter, w= -0.7. The accelerated expansion of the universe, starting at about 7 billion years, determined by BOSS measurements, also correlates well with the dominance of dark energy at 7.25 x 10⁹ years ( a= 0.65). The expansion can be attributed to Quintessence with a space force arising from a quantum space field. From our phase diagram, we also find a correlation suggesting that dark matter is a plasma form of matter similar to that which existed during the photon epoch immediately prior to recombination. Our Quantum Space Model leads to a universe which is homogeneous and isotropic without the need for inflation. The thermodynamics of expansion is consistent with BOSS data that show the process to be adiabatic and the rate of expansion decelerating during the first 6 billion years after the Big Bang. However, it became non-adiabatic and accelerating thereafter. This implies an influx of energy from a source outside the universe; it warrants consideration as a possible factor in the accelerated expansion of the universe.

Preprint ARTICLE | doi:10.3390/sci1030061

On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets

Andjelka Kovačević

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: intergalactic meteor particle; extrasolar planets; astrobiology

Online: 19 October 2019 (00:00:00 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201708.0108.v1

Full-Stokes, Multi-Frequency Radio Polarimetry of Fermi Blazars; Monitoring and Modelling

Emmanouil Angelakis, Ioannis Myserlis, Anton J Zensus

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: AGN; jets; polarisation; linear; circular; radio; polarised radiative transfer

Online: 31 August 2017 (15:25:30 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201710.0191.v1

Effelsberg Monitoring of a Sample of RadioAstron Blazars

Jun Liu, Thomas P. Krichbaum, Xiang Liu, Alex Kraus, Hayley Bignall, Yuri Y. Kovalev, Kirill V. Sokolovsky, J. Anton Zensus

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxies; active -- method; statistical -- radio continuum; ISM

Online: 31 October 2017 (04:18:48 CET)

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Preprint ARTICLE | doi:10.20944/preprints201908.0046.v1

The Discrepancy in Galaxy Rotation Curves

Roy Gomel, Tomer Zimmerman

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: dark matter; reference frames; galaxies

Online: 5 August 2019 (05:08:42 CEST)

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Preprint SHORT NOTE | doi:10.20944/preprints202002.0166.v1

The Correlation between Rotational Gravity and Magnetic Field of Celestial Body

Ying-Qiu Gu

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Earth magnetic field; celestial magnetic field; magnetic dipole; Clifford algebra; Dirac equation; spin-gravity coupling potential; curved space-time

Online: 13 February 2020 (10:48:46 CET)

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The magnetic field of the earth plays an important role in the ecosystem, and the magnetic field of celestial bodies is also important in the formation of cosmic large-scale structures, but the origin and evolution of the celestial magnetic field is still an unresolved mystery. Many hypotheses to explain the origin have been proposed, but there are some insurmountable difficulties for each one. At present, the theory widely accepted in scientific society is the dynamo model, it says that, the movement of magnetofluid inside celestial bodies, which can overcome the Ohmic dissipative effect and generate persistent weak electric current and macroscopic magnetic field. However, this model needs an initial seed magnetic field, and the true values of many physical parameters inside the celestial body are difficult to obtain, and there is no stable solution to the large range of fluid motion. These are all difficulties for the dynamo model. Furthermore, it is difficult for the dynamo to explain the correlation between the dipole magnetic field and angular momentum of a celestial body. In this paper, by calculating the interaction between spin of particles and gravity of celestial body according to Clifford algebra, we find that a rotational celestial body provides a field $\Omega^\alpha$ for spins, which is similar to the magnetic field of a dipole, and the spins of charged particles within the celestial body are arranged along the flux line of $\Omega^\alpha$, then a macroscopic magnetic field is induced. The calculation shows that the strength of $\Omega^\alpha$ is proportional to the angular momentum of the celestial body, which explains the correlation between the magnetic intensity and angular momentum. The results of this paper suggest that further study of the effects of internal variables such as density, velocity, pressure and temperature of a celestial body on $\Omega^\alpha$ may provide some new insights into the origin and evolution of celestial magnetic field.

Preprint ARTICLE | doi:10.20944/preprints201708.0041.v4

The Granularity of Gravity

Engel Roza

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: entropic gravity; Cosmological Constant; quantum gravity; dark matter

Online: 2 November 2017 (14:39:13 CET)

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Preprint ARTICLE | doi:10.20944/preprints201709.0049.v1

Towards a New Proposal for the Time Delay in Gravitational Lensing

Marco Bonici, Nicola Alchera, Nicola Maggiore

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: classical general relativity; gravitational lenses

Online: 13 September 2017 (04:54:57 CEST)

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Preprint ARTICLE | doi:10.3390/sci2030071

Lasers for Satellite Uplinks and Downlinks

Mark Dmytryszyn, Matthew Crook, Timothy Sands

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: telescopes; lightweight telescope mirrors; adaptive optics; better resolution; increased accuracy; more bandwidth; cluster of satellites; innovative platform; more capabilities into smaller packages; far-shorter time from click to customer

Online: 9 September 2020 (00:00:00 CEST)

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The use of Light Amplification by Stimulated Emission of Radiation (i.e., LASERs or lasers) by the U.S. Department of Defense is not new and includes laser weapons guidance, laser-aided measurements, even lasers as weapons (e.g., Airborne Laser). Lasers in support of telecommunications is also not new. The use of laser light in fiber optics shattered thoughts on communications bandwidth and throughput. Even the use of lasers in space is no longer new. Lasers are being used for satellite-to-satellite crosslinking. Laser communication can transmit orders-of-magnitude more data using orders-of-magnitude less power and can do so with minimal risk of exposure to the sending and receiving terminals. What is new is using lasers as the uplink and downlink between the terrestrial segment and the space segment of satellite systems. More so, the use of lasers to transmit and receive data between moving terrestrial segments (e.g., ships at sea, airplanes in flight) and geosynchronous satellites is burgeoning. This manuscript examines the technological maturation of employing lasers as the signal carrier for satellite communications linking terrestrial and space systems. The purpose of the manuscript is to develop key performance parameters (KPPs) to inform U.S. Department of Defense initial capabilities documents (ICDs) for near-future satellite acquisition and development. By appreciating the history and technological challenges of employing lasers rather than traditional radio frequency sources for satellite uplink and downlink signal carrier, this manuscript recommends ways for the U.S. Department of Defense to employ lasers to transmit and receive high bandwidth, large-throughput data from moving platforms that need to retain low probabilities of detection, intercept, and exploitation (e.g., carrier battle group transiting to a hostile area of operations, unmanned aerial vehicle collecting over adversary areas). The manuscript also intends to identify commercial sector early-adopter fields and those fields likely to adapt to laser employment for transmission and receipt.

Preprint ARTICLE | doi:10.20944/preprints201804.0380.v1

Cosmological Models in Lyra Geometry with Linearly Varying Deceleration Parameter

Kalyani Desikan

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Cosmology; Lyra Geometry; Linearly Varying Deceleration Parameter

Online: 30 April 2018 (12:17:36 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201712.0077.v2

A Cosmological View on Milgrom’s Acceleration Constant

Engel Roza

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Cosmological Constant; MOND; dark matter; dark energy; Lamda-CDM model

Online: 10 January 2018 (10:29:21 CET)

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Preprint REVIEW | doi:10.20944/preprints201805.0459.v1

Laboratory Hydrogen-Beta Emission Spectroscopy for Analysis of Astrophysical White Dwarf Spectra

Christian G Parigger, Kyle A. Drake, Christopher M Helstern, Ghaneshwar Gautam

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: white dwarfs; burning in stars; plasma diagnostics; atomic spectra; plasma spectroscopy; laser spectroscopy; laser-induced breakdown spectroscopy

Online: 31 May 2018 (05:13:00 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202005.0250.v9

On Spacetime Duality and Bounce Cosmology of a Dual Universe

Mohammed B. Al-Fadhli

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Accelerated Expansion; Fast orbital speed of outer stars; Duality; Antimatter.

Online: 29 April 2021 (09:10:40 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201907.0241.v2

Testing RNN-LSTM Forecasting with Simulated Time-Series : Exploring Univariate Sensitivity

Nachiketa Chakraborty

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: recurrent neural networks; LSTM; lightcurves; simulation; variability

Online: 31 August 2023 (10:08:17 CEST)

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With an explosion of data in the nearly every domain, from physical and environmental sciences to econometrics and even social science, we have entered a golden era of time-domain data science. In addition to ever increasing data volumes and varieties of time-series, there's a plethora of techniques available to analyses them. Unsurprisingly, machine learning approaches are very popular. In environmental sciences (ranging from climate studies to space weather/solar physics), machine learning (ML )and deep learning (DL) approaches complement the traditional data assimilation approaches. In solar and astrophysics, multiwavelength time-series or lightcurves along with observations of other messengers like gravitational waves provide a treasure trove of time-domain data for ML/DL approaches for modeling and forecasting. In this regard, deep learning algorithms such as recurrent neural networks (RNNs) should prove extremely powerful for forecasting as it has in several other domains. Such methods agnostic of the physics can only predict transient flares that are represented in the original distribution trained on (eg. coloured noise fluctuations) and not special, isolated episodes (eg. a one-off outburst like a major coronal mass ejection) potentially distinguishing them. Therefore it is vital to test robustness of these techniques ; here we attempt to make a small contribution to this by exploring sensitivity of RNNs with some rudimentary experiments. We test the performance of a very successful class of RNNs, the Long Short Term Memory (LSTM) algorithms with simulated lightcurves. As an example, we focus on univariate forecasting of time-series (or lightcurves) characteristic certain variable astrophysical objects (eg. active galactic nuclei or AGN). Specifically, we explore the sensitivity of training and test losses to key parameters of the LSTM network and data characteristics namely gaps and complexity measured in terms of number of Fourier components. We find that typically, the performances of LSTMs are better for pink or flicker noise type sources. The key parameters on which performance is dependent are batch size for LSTM and the gap percentage of the lightcurves. While a batch size of $10-30$ seems optimal, the most optimal test and train losses are under $10 \%$ of missing data for both periodic and random gaps in pink noise. The performance is far worse for red noise. This compromises detectability of transients. Thus, we show that generative models (time-series simulations) are excellent guides for use of RNN-LSTMs in building forecasting systems

Preprint ARTICLE | doi:10.3390/sci2020041

Organic Molecules: Is It Possible to Distinguish Aromatics from Aliphatics Collected by Space Missions in High-Speed Impacts?

Mark Burchell, Kathryn Harriss

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Astrobiology; Enceladus; space-missions; organic; aromatic; aliphatic

Online: 8 June 2020 (00:00:00 CEST)

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A prime site of astrobiological interest within the Solar System is the interior ocean of Enceladus. This ocean has already been shown to contain organic molecules, and is thought to have the conditions necessary for more complex organic biomolecules to emerge and potentially even life itself. This sub-surface ocean has been accessed by Cassini, an unmanned spacecraft that interacted with the water plumes ejected naturally from Enceladus. The encounter speed with these plumes and their contents, was between 5 and 15 km s⁻¹. Encounters at such speeds allow analysis of vapourised material from submicron-sized particles within the plume, but sampling micron-sized particles remains an open question. The latter particles can impact metal targets exposed on the exterior of future spacecraft, producing impact craters lined with impactor residue, which can then be analysed. Although there is considerable literature on how mineral grains behave in such high-speed impacts, and also on the relationship between the crater residue and the original grain composition, far less is known regarding the behaviour of organic particles. Here we consider a deceptively simple yet fundamental scientific question: for impacts at speeds of around 5–6 kms⁻¹ would the impactor residue alone be sufficient to enable us to recognise the signature conferred by organic particles? Furthermore, would it be possible to identify the organic molecules involved, or at least distinguish between aromatic and aliphatic chemical structures? For polystyrene (aromatic-rich) and poly(methyl methacrylate) (solely aliphatic) latex particles impinging at around 5 km s⁻¹ onto metal targets, we find that sufficient residue is retained at the impact site to permit identification of a carbon-rich projectile, but not of the particular molecules involved, nor is it currently possible to discriminate between aromatic-rich and solely aliphatic particles. This suggests that an alternative analytical method to simple impacts on metal targets is required to enable successful collection of organic samples in a fly-by Enceladus mission, or, alternatively, a lower encounter speed is required.

Preprint ARTICLE | doi:10.20944/preprints202201.0106.v1

HU - The Big Pop Cosmogenesis Equation of State

Marco Pereira

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Cosmology, Cosmogenesis, Relativity, Spacetime, Hypergeometrical Universe Theory, Dark Matter, Dark Energy, L-CDM, Big Bang, Big Pop

Online: 10 January 2022 (12:14:01 CET)

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Preprint ARTICLE | doi:10.20944/preprints201806.0422.v1

VALD: The Meeting Point of Data Producers and Data Users

Tatiana Ryabchikova, Yury Pakhomov, Nikolai Piskunov

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: stellar spectra; atomic and molecular data; databases

Online: 26 June 2018 (13:08:52 CEST)

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Preprint REVIEW | doi:10.20944/preprints201802.0062.v1

The growth of interest for astronomical X-ray polarimetry

Frédéric Marin

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: X-rays; polarimetry; general; history of astronomy

Online: 7 February 2018 (10:35:37 CET)

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Preprint ARTICLE | doi:10.20944/preprints201811.0588.v1

Articial Intelligence and Brain Simulation Probes for Interstellar Expeditions

Eray Özkural

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Artificial Intelligence, Brain Simulation

Online: 26 November 2018 (11:34:04 CET)

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We introduce a mission design for an interstellar expedition to nearby earth-like exoplanets, which our analysis determined to be Tau Ceti and Gliese 667C, at the time of analysis in 2013. We review the research problems in propulsion and AGI that must be addressed to launch an AI guided interstellar probe within 100 years. We propose a new semi-autonomous agent approach for intelligent control of the spacecraft. We introduce the concept of a semi-autonomous agent as having built-in safety guarantees that constrain operation. An autonomous agent case study is presented formulating the objective, constraints, AGI implementation of the agent based on Solomono's Alpha architecture, and adding specicity. We discuss the training required to reach human-level and trans-sapient levels of intelligence which corresponds to an entire crew of AI experts specialized in elds such as astrophysics, astromechanics, astrobiology, quantum physics, computer science, molecular biology, and so forth. We project the feasibility of the human-level AI technology based on empirical ndings in neuroscience, and nd that it should be feasible by 2030. We analyze Solomono's innity point hypothesis in light of Koomey's law about energy eciency of computing and nd that the trends in 2013 indicated an early singularity by 2035, which implies that we might encounter physical bottlenecks which will decelerate computing technology improvements signicantly. We recommend thus year 2040 for launching the probe by which date other required technologies will have been developed. We discuss the scenario of a virtual crew made of brain simulations, which is a bio-information based AI approach. We detail the subsystems of command and control, communication, scientic instrumentation, power, propulsion, navigation, and shielding. We propose a variation of ICAN-II/AIMStar propulsion which uses a positron source instead of anti-protons to initiate micro-fusion reactions. We combine the positron initiated fusion pulse propulsion scheme with a miniaturized version of the Daedelus fusion thruster obtaining high performance. We derive two mission proles one for fusion pulse propulsion, and the yet hypothetical Q-Thruster. Fusion thruster requires 132.2 years for Tau Ceti, and 233.2 years for Gliese 667C, while Q-Thruster takes only 42.3 years for Tau Ceti, and 62.5 years for Gliese 667C. We also discuss extended roles for intelligent interstellar probes such as self-reproduction via nanotechnology, refueling, construction, robotic bodies, and transmission of brain simulations.

Preprint ARTICLE | doi:10.20944/preprints201802.0170.v1

On the Expansion of Space and How to Measure It

Firmin J. Oliveira

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: universe expansion; Hubble constant; cavity finesse; cosmological redshift; strain

Online: 27 February 2018 (03:41:54 CET)

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We describe the effect of the expansion of space on the wavelength of the light beam in a Fabry-Pérot interferometer. For an instrument such as the Laser Interferometer Gravitational-Wave Observatory (LIGO), which has high sensitivity and a long period of light storage, the wavelength

λ_{L}

of laser photons are redshifted due to the expansion of space in each cavity by an amount

δ λ

given by

δ λ / λ_{L} = H_{0} τ_{s} \approx 8.8 \times 10^{- 21}

, where

H_{0} \approx 2.2 \times 10^{- 18} s^{- 1}

is the Hubble constant and

τ_{s} \approx 4 ms

is the light storage time for the cavity. Since

τ_{s}

is based on the cavity finesse

F

which depends on the laser beam full width at half maximum (FWHM)

δ ω

of each cavity, we show that a difference in finesses between the LIGO arm cavities produces a signal

h_{H} (t)

at the anti-symmetric output port given by

h_{H} (t) = 2 a_{1} H_{0} (\frac{1}{δ ω_{X} (t)} - \frac{1}{δ ω_{Y} (t)}),

where

δ ω_{X} (t)

and

δ ω_{Y} (t)

are the beam FWHM at time t, respectively, for the X and Y arm cavities and

a_{1}

is a beam proportionality constant to be determined expermentally. Assuming

a_{1} \approx 1

, then for cavity beams FWHM of

δ ω (t) \approx (523.2 \pm 31) rad . s^{- 1}

the output signal has the range

∣ h_{H} (t) ∣ \leq 1 \times 10^{- 21}

, which is detectable by advanced LIGO.

Preprint ARTICLE | doi:10.20944/preprints201812.0054.v3

The Vacuum Polarization Paradox and Its Solution

Engel Roza

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: quantum gravity; vacuum polarization; gravitational dipole; Majorana particle

Online: 5 March 2019 (11:14:31 CET)

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Preprint ARTICLE | doi:10.20944/preprints201712.0093.v1

Probing Quantum Gravity Through Strong Gravitational Lensing

Stuart Marongwe

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Quantum Gravity; Gravitational Lensing; Dark Matter; Quantum Vacuum; Graviton

Online: 14 December 2017 (12:06:01 CET)

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Preprint ARTICLE | doi:10.20944/preprints202207.0121.v6

The Big Bang Was Not the Beginning, but a Repeating Pattern of Expansion and Contraction of Space Time

Amrit Ladhani

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: big bang and big crunch; cosmology; dark energy; dark matter; gravitational force; the cyclic universe

Online: 18 December 2023 (06:27:08 CET)

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Preprint ARTICLE | doi:10.20944/preprints201803.0206.v1

Optimization of Finite-Differencing Kernels for Numerical Relativity Applications

Roberto Alfieri, Sebastiano Bernuzzi, Albino Perego, David Radice

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: numerical relativity; many-core architectures; Knight Landing; vectorization

Online: 26 March 2018 (07:53:06 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202101.0612.v1

Variable Planck’s Constant: Treated As A Dynamical Field And Path Integral

Rand Dannenberg

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Modified Gravity; variable constants; fundamental constants

Online: 29 January 2021 (11:48:01 CET)

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Preprint ARTICLE | doi:10.20944/preprints201912.0228.v1

A Modified Gravitational Explanation of the Dynamic Origin of the Stars' Rotation and Revolution

Wei Fan

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: gravity; dark matter; dark energy; Newtonian mechanics; motion

Online: 17 December 2019 (10:11:44 CET)

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Preprint ARTICLE | doi:10.20944/preprints201806.0424.v4

A Scale-Invariant, Machian Theory of Gravitation and Electrodynamics Unified

Ram Gopal Vishwakarma

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Gravitation - Fundamental Problems and General Formalism; Electrodynamics; Scale Invariance; Mach Principle; Dark Energy

Online: 3 October 2018 (15:35:51 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0147.v1

Constraints on Lorentz Invariance Violation From Optical Polarimetry of Astrophysical Objects

Fabian Kislat

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Lorentz invariance; Standard-Model extension; polarization; Active Galactic Nuclei; Gamma-ray Bursts

Online: 9 September 2018 (09:04:03 CEST)

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Working Paper REVIEW

Rotating Disk Galaxies without Dark Matter Based on Scientific Reasoning

James Feng

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: disk galaxies; galactic rotation; Newtonian dynamics; rotation curve; dark matter; mass-to-light ratio

Online: 13 November 2019 (02:37:48 CET)

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Preprint ARTICLE | doi:10.20944/preprints201905.0335.v1

An Alternative to Dark Matter?A Cosmological Model of Galaxy Rotation Using Cosmological Gravity Force, F_Λ (ALW)

Jean Perron

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: cosmological parameters numerical values; cosmology early universe; galaxies kinematic and dynamic; galaxies Coma cluster; galaxies evolution

Online: 28 May 2019 (11:00:50 CEST)

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A cosmological model was developed using the equation of state of photon gas, as well as cosmic time. The primary objective of this model is to see if determining the observed rotation speed of galactic matter is possible, without using dark matter (halo) as a parameter. To do so, a numerical application of the evolution of variables in accordance with cosmic time and a new state equation was developed to determine precise, realistic values for a number of cosmological parameters, such as energy of the universe , cosmological constant Λ, curvature of space k, energy density , age of the universe etc. Some assumptions were put forth in order to solve these equations. The current version of the model partially explains several of the observed phenomena that raise questions. Numerical application of the model has yielded the following results, among others: Initially, during the Planck era, at the very beginning of Planck time, , the universe contained a single photon at Planck temperature Planck energy in the Planck volume. During the photon inflation phase (before characteristic time ~10^-9 ), the number of original photons (alphatons) increased at each unit of Planck time and geometrical progression ~n³, where n is the quotient of cosmic time over Planck time . Then, the primordial number of photons reached a maximum of N~10⁸⁹, where it remained constant. It's primordial photons (alphatons) are still present today and represents the essential of the energy contained in the universe via the cosmological constante . Such geometric growth in the number of photons can bring a solution to the horizon problem through exchange and a photon energy volume that is in phase with that of the the volume energy of the universe. The age of the universe in cosmic time that is in line with positive energy conservation (in terms of conventional thermodynamics) and the creation of proton, neutron, electron, and neutrino masses, is ~76 [Gy] (observed . The predicted total mass (p, n, e and n), based on the Maxwell-Juttner relativistic statistical distribution, is ~7x10⁵⁰ . The predicted cosmic neutrino mass is ≤ 8.69x10^-32 (≤ 48.7 ) if based on observations of SN1987A. The temperature variation of the cosmic microwave background (CMB), as measured by Planck, can be said to be partially due to energy variations in the universe (DU/U) during the primordial baryon synthesis (energy jump from the creation of protons and neutrons). In this model, what is usually referred to as dark energy actually corresponds to the energy of the universe that has not been converted to mass, and which acts on the mass created by the energy-mass equivalence principle and the cosmological gravity field, , associated with the cosmological constant, which is high during primordial formation of the galaxies (<1 [Gy]). A look at the Casimir effect makes it possible to estimate a minimum Casimir pressure and thus determine our possible relative position in the universe at cosmic time 0,1813 (t₀/t_W=13,8 /76,1 ). Therefore, from the observed age of 13,8 [Gy], we can derive a possible cosmic age of 76,1 [Gy]. That energy of the universe, when taken into consideration during the formation of the first galaxies (< 1 [Gy]), provides a relatively adequate explanation of the non-Keplerian rotation of galactic masses. Indeed, such residual, non-baryonic energy, when considered in Newton’s gravity equation, adds the term , which can partially explain, without recourse to dark matter, the rotations of some galaxies, such as M33, UGC12591, UGC2885, NGC3198, NGC253, DDO161, UDG44, the MW and the Coma cluster. Today, in the MW, that cosmological gravity force is in the order of 10²⁶ times smaller than the conventional gravity force. The model predicts an acceleration of the mass in the universe (q~ 0,986); the energy associated with curvature is the driving force behind the expansion of the universe, rather than the energy associated with the cosmological constant . An equation to determine expansion is obtained using the energy form of the Friedmann equation relative to Planck power and cosmic time or Planck force acting at the frontier of the universe moving at c. This constant Planck force, from unknown sources, acts everywhere to the expansion of the universe as a stretching effect on the volume. Finally, the model partly explains the value a₀ of the MOND theory. Indeed, a₀ is not a true constant, but depends on the cosmological constant at the time the great structures were formed (~1 [Gy]), as well as an adjustment of the typical mass and dimension of those great structures, such as galaxies. The constant a₀is a different expression of the cosmological gravity force as expressed by the cosmological constant, Λ, acting through the energy-mass equivalent during the formation of the structures. It does not put in question the value of G.

Preprint ARTICLE | doi:10.20944/preprints202010.0320.v3

Extended General Relativity for a Curved Universe

Mohammed B. Al-Fadhli

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: General Relativity; Curved Universe

Online: 6 November 2020 (13:11:37 CET)

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Preprint ARTICLE | doi:10.20944/preprints202002.0366.v1

Energy-Momentum Tensor and Parameters in Cosmological Model

Ying-Qiu Gu

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: cosmological model; energy-momentum tensor; equation of state; cosmic curvature; cosmological constant; negative pressure; dynamic analysis

Online: 25 February 2020 (07:55:12 CET)

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Preprint ARTICLE | doi:10.20944/preprints201809.0325.v1

Angular Momentum and Energy Transfer in a Whitehead's Theory of Gravity

Luis Acedo

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: energy and angular momentum transfer; modified theories of gravity; anomalous increase of the astronomical unit

Online: 18 September 2018 (05:23:11 CEST)

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Working Paper ARTICLE

Hartle-Hawking boundary conditions as Nucleation by de Sitter Vacuum

Christian Corda, Fabiano Feleppa, Ignazio Licata

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Hartle-Hawking state; de Sitter Universe; de Sitter Projective Holography.

Online: 13 September 2019 (12:29:54 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201811.0473.v1

The Quasi Steady State Cosmology in a Radiation Dominated Phase

Raj Bali

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Quasi Steady State Cosmology, Radiation Phase

Online: 19 November 2018 (16:48:10 CET)

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Preprint ARTICLE | doi:10.20944/preprints202105.0576.v1

A Vacuum of Quantum Gravity That is Ether.

Sergey L. Cherkas, Vladimir L. Kalashnikov

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: quantum gravity; vacuum state; vacuum energy,; eicheon

Online: 24 May 2021 (15:06:43 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202003.0172.v1

UV Irradiation and Near Infrared Characterization of Laboratory Mars Soil Analog Samples: the case of Phthalic Acid, Adenosine 5’-Monophosphate, L-Glutamic Acid and L-Phenylalanine Adsorbed onto the Clay Mineral Montmorillonite in the Presence of Magnesium Perchlorate

Teresa Fornaro, John Brucato, Giovanni Poggiali, Maria Angela Corazzi, Malgorzata Biczysko, Maguy Jaber, Dionysis Foustoukos, Robert Hazen, Andrew Steele

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: molecular biosignatures; Mars; UV irradiation; infrared spectroscopy; life detection

Online: 10 March 2020 (14:10:19 CET)

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The search for molecular biosignatures at the surface of Mars is complicated by an intense irradiation in the mid- and near- ultraviolet (UV) spectral range for several reasons: (i) many astrobiologically relevant molecules are electronically excited by efficient absorption of UV radiation and rapidly undergo photochemical reactions; (ii) even though the penetration depth of UV radiation is limited, aeolian erosion continually exposes fresh material to radiation; and (iii) UV irradiation generates strong oxidants such as perchlorates that can penetrate deep into soils and cause subsurface oxidative degradation of organics.As a consequence, it is crucial to investigate the effects of UV radiation on organic molecules embedded in mineral matrices mimicking the martian soil, in order to validate hypotheses about the nature of the organic compounds detected so far at the surface of Mars by the Curiosity rover, as well as organics that will be possibly found by the next rover missions Mars 2020 and ExoMars 2020. In addition, studying the alteration of possible molecular biosignatures in the martian environment will help to redefine the molecular targets for life detection missions and devise suitable detection methods.Here we report the results of mid-UV irradiation experiments of Mars soil analog samples obtained adsorbing relevant organic molecules on a clay mineral that is quite common on Mars, i.e. montmorillonite, doped with 1 wt% of magnesium perchlorate. Specifically, we chose to investigate the photostability of a plausible precursor of the chlorohydrocarbons detected on Mars by the Curiosity rover, namely phthalic acid, along with the biomarkers of extant life L-phenylalanine and L-glutamic acid, which are proteomic amino acids, and adenosine 5’-monophosphate, which is a nucleic acid component.We monitored the degradation of these molecules adsorbed on montmorillonite through in situ spectroscopic analysis, investigating the reflectance properties of the samples in the Near InfraRed (NIR) spectral region. Such spectroscopic characterization of molecular alteration products provides support for two upcoming robotic missions to Mars that will employ NIR spectroscopy to look for molecular biosignatures, through the instruments SuperCam on board Mars 2020, ISEM, Ma_Miss and MicrOmega on board ExoMars 2020.

Preprint REVIEW | doi:10.20944/preprints202106.0597.v1

Relativistic Cosmology with an Introduction to Inflation

Muhammad Zahid Mughal, Iftikhar Ahmad, Juan Luis GARCÍA GUIRAO

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: spacetime; relativistic cosmology; big bang model; inflation

Online: 24 June 2021 (09:33:15 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201804.0212.v1

Planets, Planetary Nebulae, and Intermediate Luminosity Optical Transients (ILOTs)

Noam Soker

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: planetary nebulae: general; stars: AGB and post-AGB; stars: variables: general; stars: winds, outflows

Online: 16 April 2018 (14:05:31 CEST)

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Working Paper ARTICLE

A New Theory on Redshift of Photons

Xiaoping Hu

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: temperature; photon; spectrum line; redshift; Doppler redshift; Hubble’s Law; Universe Expansion; cosmologic redshift; Big Bang Theory

Online: 23 September 2019 (06:27:32 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202002.0412.v1

Simplification of Galactic Dynamic equations

Ying-Qiu Gu

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Galactic dynamics; Spiral structure; Bared spiral structure; Density wave; Gravitational retarded potential

Online: 27 February 2020 (16:10:59 CET)

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Most fully developed galaxies have vivid spiral structure, but the formation and evolution of spiral structure is still a mystery that is not fully understood in astrophysics. We find that the currently used equations of galactic dynamics contain some unreasonable components. In this paper, the following three working assumptions are introduced to simplify the galactic structural equations. 1. In the research of large-scale structure, the retarded potential of the gravitational field should be taken into account. The propagating time of the gravitational field from center to border is longer than the revolution periods of the stars near the center of galaxy. Newton's gravitational potential is unreasonable for such case, and the weak field and low velocity approximation of Einstein's field equation should be adopted. 2. The stars in a fully developed galaxy should be zero-pressure and inviscid fluid, and the equation of motion is different from that of ordinary continuum mechanics. Stars move along geodesics. 3. The structure of the galaxy is only related to the total mass density distribution. The equation of state of dark halo is different from that of ordinary luminous interstellar matter, so their trajectories are also very different. Dark halo and ordinary matter in galaxy are automatically separated. The total mass density distribution can be presupposed according to the observation data, and then it can be determined by comparing the solution of the equations with the observed data. These assumptions and treatments are supported by theory and observation. The variables of the equations of simplified galactic dynamics are separated from each other, and the equations are well-posed and can be solved according to a definite procedure. Therefore, this simplified dynamic equation system provides a more reasonable and practical framework for the further study of galactic structure, and can solve many practical problems. Besides, it is closely related to the study of dark energy and dark matter.

Preprint ARTICLE | doi:10.20944/preprints201808.0544.v1

Accelerated Frames and Galactic Rotation Curves

Sergio C. Ulhoa, Fernando L. Carneiro

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: accelerated frames; galactic rotation curve; dark matter

Online: 31 August 2018 (10:00:39 CEST)

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Preprint REVIEW | doi:10.20944/preprints202005.0523.v1

Is There Water Ice in the Lunar Polar Craters?

Tianxi Sun

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: water ice; hydroxyl radicals; methanol; hydroxyl groups; spectral identity; confusion

Online: 31 May 2020 (21:58:06 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201807.0149.v1

Binary Interactions, High-Speed Outflows and Dusty Disks during the Agb-to-Pn Transition

Raghvendra Sahai

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: planetary nebulae; AGB & post-AGB stars; binarity; accretion disks; jets; mass-loss; circumstellar matter; (sub)millimeter interferometry; ultraviolet radiation; X-rays

Online: 9 July 2018 (13:58:51 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201808.0019.v1

X-ray Shaping of Planetary Nebulae

Martin A Guerrero

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: planetary nebula; X-ray; stellar evolution

Online: 1 August 2018 (12:04:48 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201903.0075.v1

Correlation between Intense Solar Energetic Particle Fluxes and Atmospheric Weather Extremes

Georgios Anagnostopoulos, Sofia Anna Menesidou, Vasilios G. Vassiliadis, Alexandros Rigas

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: extreme weather events; heat waves; sun-earth relationships; sun and weather; space weather and extreme atmospheric events; global atmospheric anomalies; SEP events and weather; SEP and NAO; gulf stream and heat waves

Online: 6 March 2019 (11:01:50 CET)

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In the past two decades the world experienced an exceptional number of unprecedented extreme weather events, some causing major human suffering and economic damage, such as the March 2012 heat event, which was called “Meteorological March Madness.” From the beginning of space era a correlation of solar ﬂares with pressure changes in atmosphere within 2–3 days or even less was reported. In this study we wanted to test the possible relation of highly warm weather events in North-East America with Solar Energetic Particle (SEP) events. For this reason we compared ground temperatures T_M in Madison, Wisconsin, with energetic particle fluxes P measured by the EPAM instrument onboard the ACE spacecraft. In particular, we elaborated case events and the results of a statistical study of the SEP events related with the largest (Dst ≤ −150nT) Coronal Mass Ejection (CME)-induced geomagnetic storms, between with the years 1997–2015. The most striking result of our statistical analysis is a very significant positive correlation between the highest temperature increase_.ΔT_M and the time duration of the temperature increase ΔT_M (r = 0.8, p <0.001) at “winter times” ( r = 0.5, p , 0.01 for the whole sample of 26 SEP examined events). The time response of T_M to P was found to be in general short (a few days), but in the case of March 2015, during a gradual P8 increase, a cross-correlation test indicated highest c.c. within 1 day (p < 0.05). The March 2012 “meteorological anomaly” was elaborated in the case of South-East Europe, where, beside a period of strong winds and rainfall (6-13.3.2012), intense precipitation in North-East Greece (Alexandroupoli) were found to be correlated with distinct high energy flux enhancements. A rough theoretical interpretation is discussed for the space—atmospheric extreme weather relationship we found. However, much work should be done to achieve early warning of space weather dependent extreme meteorological events. Such future advances in understanding the relationships between space weather and extreme atmospheric events would improve atmospheric models and help people’s safety, health and life.

Preprint ARTICLE | doi:10.20944/preprints201912.0125.v1

Dark Energy Stars with Quadratic Equation of State

Manuel Malaver, Hamed Kasmaei

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: dark energy; stellar configurations; anisotropic fluid distribution; quadratic equation of state; Einstein-Maxwell field equations; metric coefficients

Online: 10 December 2019 (04:42:44 CET)

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Preprint BRIEF REPORT | doi:10.20944/preprints202007.0198.v1

About Dark Matter and Gravitation

Alain Haraux

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: gravitation; dark matter; redshift; big bang

Online: 9 July 2020 (17:25:47 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201810.0273.v1

Russian-German Astroparticle Data Life Cycle Initiative

Igor Bychkov, Andrey Demichev, Julia Dubenskaya, Oleg Fedorov, Andreas Haungs, Andreas Heiss, Yulia Kazarina, Elena Korosteleva, Dmitriy Kostunin, Alexander Kryukov, Andrey Mikhailov, Minh-Duc Nguyen, Stanislav Polyakov, Evgeny Postnikov, Alexey Shigarov, Dmitry Shipilov, Achim Streit, Viktoria Tokareva, Doris Wochele, Jürgen Wochele, Dmitry Zhurov

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: astroparticle physics, cosmic rays, data life cycle management, data curation, meta data, big data, deep learning, open data

Online: 12 October 2018 (14:48:32 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201806.0378.v1

Simulations and Modeling of Intermediate Luminosity Optical Transients and Supernova Impostors

Amit Kashi

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: stellar evolution; late stage stellar evolution; binarity; transients; planetary nebulae

Online: 25 June 2018 (10:30:21 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0310.v1

Binary Star Database BDB: New Developments and Applications

Oleg Malkov, Aleksey Karchevsky, Pavel Kaygorodov, Dana Kovaleva, Nikolay Skvortsov

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: astronomical data bases; catalogues; binaries: general; cataclysmic variables

Online: 17 September 2018 (12:53:07 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201811.0257.v1

Effective Apsidal Precession in Oblate Coordinates

Abraao J. S. Capistrano, Paola T. Z. Seidel, Luís A. Cabral

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: perihelion; gravity

Online: 12 November 2018 (04:20:50 CET)

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Preprint ARTICLE | doi:10.20944/preprints201810.0722.v1

Bianchi Type I Cosmological Models with Expansion Driven by Particle Creation

Kalyani Desikan

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: cosmology; Bianchi Type I; particle creation; open thermodynamic system; constant deceleration parameter; accelerated expansion; late time acceleration

Online: 30 October 2018 (09:36:05 CET)

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Preprint REVIEW | doi:10.20944/preprints201811.0195.v1

The Origin of the Most Energetic Galactic Cosmic Rays: Supernova Explosions into Massive Star Plasma Winds

Peter Biermann, Philipp Kronberg, Michael Allen, Athina Meli, Eun-Suk Seo

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Cosmic Rays; Massive Star Supernovae; Cosmic Ray Knee and Ankle.

Online: 8 November 2018 (09:53:33 CET)

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We propose that the high energy Cosmic Ray particles around the spectral turn-down commonly called the {\it knee} and up to the upturn, commonly called the {\it ankle}, mostly come from Blue Super Giant star explosions. At the upturn, i.e. the {\it ankle}, Cosmic Rays probably switch to another source class, most likely extragalactic sources. To show this we recently compiled a set of Radio Supernova data to list the magnetic field, shock speed and radius scale (Biermann et al. 2018) \cite{Biermann18}. Using particle acceleration theory at shocks, those numbers can be transformed into characteristic {\it knee} and {\it ankle} energies. Without adjusting any free parameters both of these observed energies are directly indicated by the supernova data. We now proceed to the next step in the argument, and use the Supernova Remnant data of the starburst galaxy M82. Assuming that they are Blue Supergiant star explosions, the shock will race to their outer edge with a magnetic field that follows ${B (r) \, r \, \sim \, const.}$. We argue that the shock runs through the entire magnetic plasma wind region at full speed all the way out to the wind-shell, which is of order parsec scale. The speed is observed to be $\sim \, 0.1 \, c$ at about ${10^{16} \, {\rm cm}}$ radius in the plasma wind. This demonstrates how Blue Supergiant star explosions can provide the Cosmic Ray particles across the {\it knee} and up to the {\it ankle} energy range. The data from the CREAM (Cosmic Ray Energetics and Mass Experiment) mission will test this cosmic ray concept which is reasonably well grounded in two independent radio supernova data sets. The next step in developing our understanding is to obtain accurate Cosmic Ray data near to the {\it knee}, and use unstable isotopes of Cosmic Ray nuclei at high energy to probe the "piston" driving the explosion. We plan to combine these data with the physics of the budding black hole which is probably forming in each of these stars to learn more.

Preprint ARTICLE | doi:10.20944/preprints201903.0112.v1

Lukewarm Blackhole in a Nash-Greene Framework

Abraão J. S. Capistrano

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: extra-dimensions; gravity; Cosmological constant; Black-holes

Online: 11 March 2019 (07:49:26 CET)

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Preprint ARTICLE | doi:10.20944/preprints201811.0628.v1

Some String Cosmological Models in Bianchi Type III Space-Time with Magnetic Field and Vacuum Energy Density

Raj Bali, Subhash Bola

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: String, Cosmological, Bianchi Type III, Magnetic Field, Vacuum Energy Density.

Online: 30 November 2018 (10:13:50 CET)

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Preprint BRIEF REPORT | doi:10.20944/preprints201905.0388.v1

The Dark Sector in the Baryon Phase Transition Cosmology

Frederick J. Mayer

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: dark matter; dark energy; Compton composites; tresinos

Online: 31 May 2019 (11:26:27 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201903.0107.v1

On the Dynamics of Rotationally Supported Galaxies

Ramzi Suleiman

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Dark matter; galaxies; galaxy rotation curve; radial acceleration relation.

Online: 8 March 2019 (09:58:33 CET)

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Preprint ARTICLE | doi:10.20944/preprints201809.0187.v1

The Cosmological Perturbed Lightcone Gauge

Maye Elmardi

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: general relativity; past lightcone gauge; direct observational approach; cosmological observables; galaxy surveys; galaxy number count; density contrast; overdensity; cosmological perturbations

Online: 11 September 2018 (08:08:39 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0283.v1

Detection of Periodic Radio Signal from the Blazar J1043+2408

Gopal Bhatta

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: supermassive black holes: non-thermal radiation; active galactic nuclei: BL lacertae objects: individual: J1043+2408; galaxies: jets; method: time series analysis

Online: 17 September 2018 (06:00:08 CEST)

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Preprint HYPOTHESIS | doi:10.20944/preprints202012.0680.v1

Is Dark Matter Light?

Lorne Hofstetter

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: dark matter; Milky Way dark mater halo; galaxy kinematics; rotation curves; cosmology; dark energy

Online: 28 December 2020 (11:02:57 CET)

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Preprint ARTICLE | doi:10.20944/preprints201904.0121.v1

Astrometric Solar-System Anomalies and Evolutionary Physical Constants

Rajendra P. Gupta

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: pioneer anomaly; AU anomaly; astronomical unit; varying physical constant; VSL; LLR; moon eccentricity

Online: 10 April 2019 (08:38:46 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201806.0279.v2

SpArcFiRe: Enhancing Spiral Galaxy Recognition using Arm Analysis and Random Forests

Pedro Silva, Leon T. Cao, Wayne B. Hayes

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: galaxy morphology, machine learning; data analysis; object classification

Online: 22 October 2018 (13:01:42 CEST)

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Preprint ARTICLE | doi:10.20944/preprints202109.0004.v2

Spirals and Rings in Barred Galaxies by the ROTASE Model

Hongjun Pan

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: ROTASE model; formation of spiral arms; X-matter; black hole; matter conversion; hydrogen generation; chain-link; single ring; double rings; ring crossing

Online: 2 November 2021 (17:48:35 CET)

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Preprint ARTICLE | doi:10.20944/preprints202203.0061.v1

A Beacon in the Galaxy: Updated Arecibo Message for Potential FAST and SETI Projects

Jonathan H. Jiang, Hanjie Li, Matthew Chong, Qitian Jin, Philip E. Rosen, Xiaoming Jiang, Kristen A. Fahy, Stuart F. Taylor, Zhihui Kong, Jamilah Hah, Zonghong Zhu

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Galaxy; Interstellar; Radio Message; Civilization; Earth; Binary; Radio Telescope

Online: 3 March 2022 (10:24:20 CET)

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Preprint ARTICLE | doi:10.20944/preprints201904.0119.v1

Evolutionary Physical Constants in Einstein's Field Equations and the Redshift

Rajendra P. Gupta

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: cosmology theory; cosmological parameters; galaxies; distances and redshifts; variable physical constants; VSL

Online: 10 April 2019 (08:25:53 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201903.0284.v1

The Effect of the Brane-Dicke Coupling Parameter on Weak Gravitational Lensing by Wormholes and Naked Singularities

Wajiha Javed, Rimsha Babar, Ali Övgün

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Deflection of light, Gravitational lensing, Wormhole, Gauss-Bonnet theorem, Brane-Dicke gravity

Online: 29 March 2019 (12:18:07 CET)

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Preprint ARTICLE | doi:10.20944/preprints202103.0279.v1

Resolution of the Faint Young Sun Paradox via the Expanding Earth and Radiation Balance Equilibrium Hypothesis

Golden Gadzirayi Nyambuya

Subject: Physical Sciences, Astronomy And Astrophysics Keywords: Expanding Earth; Exolife; Faint Young Sun Paradox; Radiation Balance Equation.

Online: 10 March 2021 (13:07:09 CET)

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