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Related papers: Turnaround radius in $\Lambda$CDM, and dark matter…

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We study the shadow of a charged rotating black hole in $f(R)$ gravity. This black hole is characterized by mass, $M$, spin, $a$, electric charge, $Q$ and $R_{0}$ which is proportional to cosmological constant. We analyze the image of the…

General Relativity and Quantum Cosmology · Physics 2022-10-06 Sara Dastan , Reza Saffari , Saheb Soroushfar

Recent literature has seen an ongoing discussion on the limiting mass of strongly magnetized white dwarfs, since such objects may prove to be a source of over-luminous type-Ia supernovae. In an earlier paper, we have presented the…

Solar and Stellar Astrophysics · Physics 2016-01-20 Prasanta Bera , Dipankar Bhattacharya

The concept of turnaround surface in an accelerating universe is generalized to arbitrarily large deviations from spherical symmetry, to close the gap between the idealized theoretical literature and the real world observed by astronomers.…

General Relativity and Quantum Cosmology · Physics 2021-03-03 Andrea Giusti , Valerio Faraoni

This paper presents an investigation of cosmological dynamics of tachyon fluid coupled to varyingmass dark matter particles in the background of spatially flat FLRW universe. The mechanism of varying mass particles scenario assumes the mass…

General Relativity and Quantum Cosmology · Physics 2025-07-22 Goutam Mandal , Sudip Mishra , Abdulla Al Mamon , Sujay Kr. Biswas

The observed number of dwarf galaxies as a function of rotation velocity is significantly smaller than predicted by the standard model of cosmology. This discrepancy cannot be simply solved by assuming strong baryonic feedback processes,…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Aurel Schneider , Sebastian Trujillo-Gomez , Emmanouil Papastergis , Darren S. Reed , George Lake

In this paper, we consider a recently proposed model of Dark Energy (DE) know as Modified Holographic Ricci DE (MHRDE) (which is function of the Hubble parameter and its first derivative with respect to the cosmic time $t$) in the light of…

General Physics · Physics 2017-05-31 Antonio Pasqua , Surajit Chattopadhyay , Iuliia Khomenko

We propose a revised cosmological scenario that extends the $\Lambda$ Cold Dark Matter ($\Lambda$CDM) framework by incorporating metric $f(R)$ gravity in the Jordan frame. In this model, the dark energy component arises from a non-minimally…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-08 Giovanni Montani , Luis A. Escamilla , Nakia Carlevaro , Eleonora Di Valentino

We present strong evidence for dynamical dark energy that challenges the standard $\Lambda$CDM model. Several dark energy scenarios are explored, including $\omega_0\omega_a$CDM, logarithmic, exponential, JBP, and BA parameterizations,…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Himanshu Chaudhary , Salvatore Capozziello , Subhrat Praharaj , Shibesh Kumar Jas Pacif , G. Mustafa

We use the cosmic shear data from the Canada-France-Hawaii Telescope Lensing Survey to place constraints on $f(R)$ and {\it Generalized Dilaton} models of modified gravity. This is highly complimentary to other probes since the constraints…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-21 Joachim Harnois-Déraps , Dipak Munshi , Patrick Valageas , Ludovic van Waerbeke , Philippe Brax , Peter Coles , Luca Rizzo

A simple connection between mass M of a particle or a body and time t is proposed. The flow of time t depends on the relativechange of mass, i.e \frac{\Delta M}{M}=- \mu dt, where \mu is unknown parameter. Some of the simplest consequences…

Nuclear Theory · Physics 2007-05-23 Elmir Dermendjiev

Given the recently deduced relationship between X-ray temperatures and stellar velocity dispersions (the "T-sigma relation") in an optically complete sample of elliptical galaxies (Davis & White 1996), we demonstrate that L>L_* ellipticals…

Astrophysics · Physics 2009-10-31 Michael Loewenstein , Raymond E. White

We perform a dynamical system analysis of Myrzakulov or F(R, T) gravity, which is a subclass of affinely connected metric theories, where ones uses a specific but non-special connection, which allows for non-zero curvature and torsion…

General Relativity and Quantum Cosmology · Physics 2022-11-30 G. Papagiannopoulos , Spyros Basilakos , Emmanuel N. Saridakis

It is suggested that an understanding of blackbody radiation within classical physics requires the presence of classical electromagnetic zero-point radiation, the restriction to relativistic (Coulomb) scattering systems, and the use of…

Classical Physics · Physics 2010-05-17 Timothy H. Boyer

The Luminous Convolution Model (LCM) demonstrates that it is possible to predict the rotation curves of spiral galaxies directly from estimates of the luminous matter. We consider two frame-dependent effects on the light observed from other…

Astrophysics of Galaxies · Physics 2014-07-30 S. Cisneros , N. S. Oblath , J. A. Formaggio , R. A. Ott , D. Chester , D. J. Battaglia , A. Ashley , R. Robinson , A. Rodriguez

A disk-shaped universe (encompassing the observable universe) rotating globally with an angular speed equal to the Hubble constant is postulated. It is shown that dark energy and dark matter are cosmic inertial effects resulting from such a…

General Physics · Physics 2016-06-03 Serkan Zorba

We consider a cosmological model in which a fraction $f$ of the Dark Matter (DM) is allowed to decay in an invisible relativistic component, and compute the resulting constraints on both the decay width (or inverse lifetime) $\Gamma$ and…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Vivian Poulin , Pasquale D. Serpico , Julien Lesgourgues

We study a model of the dark energy which exhibits a rapid change in its equation of state w(z), such as occurs in vacuum metamorphosis. We compare the model predictions with CMB, large scale structure and supernova data and show that a…

Astrophysics · Physics 2007-05-23 B. A. Bassett , M. Kunz , J. Silk , C. Ungarelli

We show that an interaction between dark matter and dark energy generically results in an effective dark energy equation of state of w<-1. This arises because the interaction alters the redshift-dependence of the matter density. An observer…

Astrophysics · Physics 2010-03-26 Subinoy Das , Pier Stefano Corasaniti , Justin Khoury

Kinematical and dynamical properties of a generic inhomogeneous cosmological model, spatially averaged with respect to free-falling (generalized fundamental) observers, are investigated for the matter model irrotational dust. Paraphrasing a…

General Relativity and Quantum Cosmology · Physics 2013-06-12 Thomas Buchert , Charly Nayet , Alexander Wiegand

Traditional dark matter models, eg. WIMPs, assume dark matter is weakly coupled to the standard model so that elastic scattering between dark matter and baryons can be described perturbatively by Born approximation. Most direct detection…

High Energy Physics - Phenomenology · Physics 2021-12-03 Xingchen Xu , Glennys R. Farrar