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Related papers: Probing fundamental physics using compact astrophy…

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We discuss the consequences of the accretion of dark matter (DM) particles on compact stars such as white dwarfs and neutron stars. We show that in large regions of the DM parameter space, these objects are sensitive probes of the presence…

Astrophysics · Physics 2008-11-26 Gianfranco Bertone , Malcolm Fairbairn

We present a systematic investigation of the cosmological constant effects in compact stars interiors in the framework of Einstein's gravity. Consideration of a cosmological constant $\Lambda$ in compact stars is motivated by the mechanism…

High Energy Astrophysical Phenomena · Physics 2019-02-05 Noshad Khosravi Largani , David E. Alvarez-Castillo

We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Carsten van de Bruck , Jurgen Mifsud , Nelson J. Nunes

Calculation of the Dirac hydrogen atom spectrum in the framework of dynamical fine structure constant (alpha) variability discloses a small departure in the laboratory from Sommerfeld's formula for the fine structure shifts, possibly…

Astrophysics · Physics 2007-05-23 Jacob D. Bekenstein

We show that observational limits on the possible time variation of constants of Nature are significantly affected by allowing for both space and time variation. Bekenstein's generalisation of Maxwell's equations to allow for cosmological…

Astrophysics · Physics 2009-10-31 John D. Barrow , Chris O'Toole

Accurately measuring the masses of white dwarf stars is crucial in many astrophysical contexts (e.g., asteroseismology and cosmochronology). These masses are most commonly determined by fitting a model atmosphere to an observed spectrum;…

Solar and Stellar Astrophysics · Physics 2016-10-10 T. A. Gomez , M. H. Montgomery , T. Nagayama , D. P. Kilcrease , D. E. Winget

We investigate neutrino oscillation in the field of an axially symmetric space-time, employing the so-called $q$-metric, in the context of general relativity. Following the standard approach, we compute the phase shift invoking the weak and…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Kuantay Boshkayev , Orlando Luongo , Marco Muccino

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their amazing macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2010-01-11 Pierre M. Pizzochero

Spatial and temporal variations in the electron-to-proton mass ratio, mu, and in the fine-structure constant, alpha, are predicted in non-Standard models aimed to explain the nature of dark energy. Among them the so-called chameleon-like…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-20 S. A. Levshakov , I. I. Agafonova , P. Molaro , D. Reimers

We investigate the impact of a hypothetical bosonic dark matter (DM) candidate, the sexaquark, on the fundamental ($f$-mode) oscillations of neutron stars (NSs). By varying the DM particle mass and considering different core compositions…

Nuclear Theory · Physics 2026-03-11 Mahboubeh Shahrbaf , Prashant Thakur , Davood Rafiei Karkevandi

A rotating star may be modeled as a continuous system of particles attracted to each other by gravity and with a given total mass and prescribed angular velocity. Mathematically this leads to the Euler-Poisson system. A white dwarf star is…

Analysis of PDEs · Mathematics 2019-08-07 Walter Strauss , Yilun Wu

It is possible that fundamental constants may not be constant at all. There is a generally accepted view that one can only talk about variations of dimensionless quantities, such as the fine structure constant $\alpha_{\rm e}\equiv…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Adam Moss , Ali Narimani , Douglas Scott

Recent developments in the spectropolarimetric study of compact objects, specifically black holes (stellar and massive) and neutron stars are reviewed. The lectures are organized around five topics: disks, jets, outflows, neutron stars and…

Astrophysics · Physics 2007-05-23 Roger Blandford , Eric Agol , Avery Broderick , Jeremy Heyl , Leon Koopmans , Hee-Won Lee

The dense material in a compact star from a supernova remnant is beyond terrestrial experimentation, so phenomenological modeling is used to match astrophysical observations. This is crucial due to the complex sensitivity of compact star…

High Energy Astrophysical Phenomena · Physics 2025-07-17 Vivek Baruah Thapa , Anil Kumar , Vishal Parmar , Monika Sinha

We use basic physics and simple mathematics accessible to advanced undergraduate students to estimate the main properties of neutron stars. We set the stage and introduce relevant concepts by discussing the properties of "everyday" matter…

Solar and Stellar Astrophysics · Physics 2016-08-17 Andreas Reisenegger , Felipe S. Zepeda

Strong interaction physics under extreme conditions of high temperature and/or density is of central interest in modern nuclear physics for experimentalists and theorists alike. In order to investigate such systems, model approaches that…

Solar and Stellar Astrophysics · Physics 2013-10-23 S. Schramm , V. Dexheimer , R. Negreiros , J. Steinheimer , T. Schürhoff

Close-orbit binaries consisting of two compact objects are a center of attention because of the detection of gravitational-radiation-induced mergers. The creation of close, compact-object binaries involves physical processes that are not…

Astrophysics of Galaxies · Physics 2018-05-25 Rosanne Di Stefano

We investigate the cosmological consequences of a simple theory in which the electric charge $e$ is allowed to vary. The theory is locally gauge and Lorentz invariant, and satisfies general covariance. We find that in this theory the fine…

Astrophysics · Physics 2014-10-13 H. B. Sandvik , J. D. Barrow , J. Magueijo

The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…

Astrophysics · Physics 2008-04-09 S. Geier , C. Karl , H. Edelmann , U. Heber , R. Napiwotzki

This paper gives an overview of the properties of all possible equilibrium sequences of compact strange-matter stars with nuclear crusts, which range from strange stars to strange dwarfs. In contrast to their non-strange counterparts,…

Astrophysics · Physics 2007-05-23 F. Weber , Ch. Schaab , M. K. Weigel , N. K. Glendenning