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Mass estimates of white dwarfs via electromagnetic methods, often differ from those obtained through gravitational redshift measurements, in some cases with discrepancies ranging in $5-15\%$ across independent datasets. Although many of the…

高能天体物理现象 · 物理学 2025-11-04 Jorge Castelo Mourelle , Nicolas Sanchis-Gual , José A. Font , Juan Calderón Bustillo

Type Ia supernovae, sparked off by exploding white dwarfs of mass close to Chandrasekhar limit, play the key role to understand the expansion rate of universe. However, recent observations of several peculiar type Ia supernovae argue for…

太阳与恒星天体物理 · 物理学 2013-02-19 Upasana Das , Banibrata Mukhopadhyay

Probing the existence of hypothetical particles beyond the Standard model often deals with extreme parameters: large energies, tiny cross-sections, large time scales, etc. Sometimes laboratory experiments can test required regions of…

高能天体物理现象 · 物理学 2021-10-26 P. Tinyakov , M. S. Pshirkov , S. B. Popov

We study the equilibrium structures of white dwarfs with dark matter cores formed by non-self-annihilating dark matter DM particles with mass ranging from 1 GeV to 100 GeV, which are assumed to form an ideal degenerate Fermi gas inside the…

宇宙学与河外天体物理 · 物理学 2013-06-18 S. -C. Leung , M. -C. Chu , L. -M. Lin , K. -W. Wong

We perform calculations of white dwarfs endowed with strong magnetic fields. White dwarfs are the progenitors of supernova Type Ia explosions and they are widely used as candles to show that the Universe is expanding and accelerating.…

太阳与恒星天体物理 · 物理学 2017-06-28 B. Franzon , S. Schramm

We use WMAP5 and other cosmological data to constrain model parameters in quintessence cosmologies, focusing also on their shift when we allow for non-vanishing neutrino masses. The Ratra-Peebles (RP) and SUGRA potentials are used here, as…

宇宙学与河外天体物理 · 物理学 2010-05-28 G. La Vacca , J. R. Kristiansen

A single parameter, the gravitational growth index \gamma, succeeds in characterizing the growth of density perturbations in the linear regime separately from the effects of the cosmic expansion. The parameter is restricted to a very narrow…

天体物理学 · 物理学 2010-11-05 Eric V. Linder , Robert N. Cahn

Positivity bounds - the consequences of requiring a unitary, causal, local UV completion - place strong restrictions on theories of dark energy and/or modified gravity. We derive and investigate such bounds for Horndeski scalar-tensor…

宇宙学与河外天体物理 · 物理学 2020-07-28 Scott Melville , Johannes Noller

In this work we study the magnitude-redshift relation of a non-standard cosmological model. The model under consideration was firstly investigated within a special case of metric-affine gravity (MAG) and was recently recovered via different…

广义相对论与量子宇宙学 · 物理学 2009-04-03 Dirk Puetzfeld , Xuelei Chen

We revise existing limits on the D-dimensional Planck scale M_D from the nonobservation of microscopic black holes produced by high energy cosmic neutrinos in scenarios with D=4+n large extra dimensions. Previous studies have neglected the…

高能物理 - 唯象学 · 物理学 2009-11-10 Luis A. Anchordoqui , Jonathan L. Feng , Haim Goldberg , Alfred D. Shapere

We study the invariant Planck scale correction to the thermodynamics of the ideal Fermi gas. We have considered the modified dispersion relation and the cut-off to the maximum possible momentum/energy (Planck energy) of the non-interacting…

广义相对论与量子宇宙学 · 物理学 2019-07-10 Dheeraj Kumar Mishra , Nitin Chandra

The accelerating expansion of our universe at present could be driven by an unknown energy component (Dark Energy) or a modification of general relativity (Modified Gravity). In this note we revisit the constraints on a phenomenological…

宇宙学与河外天体物理 · 物理学 2009-08-03 Jun-Qing Xia

We discuss the feasibility of using astrophysical observations of white dwarfs as probes of fundamental physics. We quantify the effects of varying fundamental couplings on the white dwarf mass-radius relation in a broad class of…

宇宙学与河外天体物理 · 物理学 2017-10-17 D. M. N. Magano , J. M. A. Vilas Boas , C. J. A. P. Martins

The equation of state of the electron degenerate gas in a white dwarf is usually treated by employing the ideal dispersion relation. However, the effect of quantum gravity is expected to be inevitably present and when this effect is…

广义相对论与量子宇宙学 · 物理学 2019-01-08 Arun Mathew , Malay Kumar Nandy

We explore the luminosity L of magnetized white dwarfs and its effect on the mass-radius relation. We self-consistently obtain the interface between the electron degenerate gas dominated inner core and the outer ideal gas surface layer or…

太阳与恒星天体物理 · 物理学 2020-06-19 Abhay Gupta , Banibrata Mukhopadhyay , Christopher A. Tout

In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively.…

广义相对论与量子宇宙学 · 物理学 2017-12-20 G. A. Carvalho , R. V. Lobato , P. H. R. S. Moraes , José D. V. Arbañil , R. M. Marinho , E. Otoniel , M. Malheiro

We construct parameter sets of the relativistic mean-field model fitted to the recent constraints on the asymmetry energy $J$ and the slope parameter $L$ for pure neutron matter. We find cases of unphysical behaviour, i.e.\ the appearance…

高能天体物理现象 · 物理学 2018-12-19 Nadine Hornick , Laura Tolos , Andreas Zacchi , Jan-Erik Christian , Jürgen Schaffner-Bielich

Interest has focussed recently on low energy implications of a nontrivial scale invariant sector of an effective field theory with an IR fixed point, manifest in terms of ``unparticles'' with peculiar properties. If unparticle stuff exists…

高能物理 - 唯象学 · 物理学 2008-12-30 Haim Goldberg , Pran Nath

We revisit astrophysical constraints on models with an ultra-light gravitino, in particular extending the analysis to more general models and the case of R-parity breaking. These constraints allow to restrict the value of the gravitino mass…

高能物理 - 唯象学 · 物理学 2015-07-20 Riccardo Catena , Laura Covi , Timon Emken

We develop a pipeline to set new constraints on scale-independent modified gravity, from the galaxy power spectrum in redshift space of BOSS DR12. The latter is modelled using the effective field theory of large-scale structure up to 1-loop…

宇宙学与河外天体物理 · 物理学 2023-04-19 Lorenzo Piga , Marco Marinucci , Guido D'Amico , Massimo Pietroni , Filippo Vernizzi , Bill S. Wright