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Related papers: Testing energy non-additivity in white dwarfs

200 papers

The white dwarf luminosity function is well understood in terms of standard model physics and leaves little room for exotic cooling mechanisms related to the possible existence of new weakly interacting light particles. This puts…

High Energy Physics - Phenomenology · Physics 2015-06-17 Lorenzo Ubaldi

If dark matter is ultra-light and has certain Standard Model interactions, it can change the mass-radius relation of white dwarf stars. The coherence length of ultra-light dark matter imparts spatial correlations in deviations from the…

Solar and Stellar Astrophysics · Physics 2025-10-02 Nicole R. Crumpler , Nadia L. Zakamska , Gautham Adamane Pallathadka , Kareem El-Badry

The white dwarf luminosity function, which provides information about their cooling, has been measured with high precision in the past few years. Simulations that include well known Standard Model physics give a good fit to the data. This…

High Energy Physics - Phenomenology · Physics 2015-06-15 Herbert K. Dreiner , Jean-François Fortin , Jordi Isern , Lorenzo Ubaldi

We present a new magnetic-atmosphere model code for obtaining synthetic spectral fluxes of hydrogen-rich magnetic white dwarfs. To date, observed spectra have been analyzed with models that neglect the magnetic field's effects on the atomic…

Solar and Stellar Astrophysics · Physics 2024-07-17 Matías Vera-Rueda , René D. Rohrmann

The influence of the magnetic field on process of the accretion onto White Dwarfs in Cataclysmic Variables (CVs) is discussed. Except for the Polars or AM Her objects, the strength of magnetic field can not be measured directly in CVs by…

Astrophysics · Physics 2009-11-10 G. H. Tovmassian

Quantum gravity is studied in a semiclassical approximation and it is found that to first order in the Planck length the effect of quantum gravity is to make the low energy effective spacetime metric energy dependent. The diffeomorphism…

High Energy Physics - Theory · Physics 2009-11-11 Lee Smolin

The mass-radius relationship of white dwarfs (WDs) is one of their defining characteristics, largely derived from electron degeneracy pressure. We present a model-independent study of the observed mass-radius relationship in WD binaries of…

Solar and Stellar Astrophysics · Physics 2024-08-29 Jin Lim , Ji-Yu Kim , Maurice H. P. M. van Putten

As part of our laboratory investigation of the theoretical line profiles used in white dwarf atmosphere models, we extend the electron-density ($n_{\rm e}$) range measured by our experiments to higher densities (up to…

Solar and Stellar Astrophysics · Physics 2016-09-30 Ross E. Falcon , J. E. Bailey , T. A. Gomez , M. Schaeuble , T. Nagayama , M. H. Montgomery , D. E. Winget , G. A. Rochau

We study the sensitivity of weak lensing by large scale structures to the evolution of dark energy. We explore a 2-parameters model of dark energy evolution, inspired by tracking quintessence models. To this end, we compute the likelihood…

Astrophysics · Physics 2008-11-26 Karim Benabed , Ludovic Van Waerbeke

We have searched for large deviations from Newtonian gravity by means of a microcantilever-based Cavendish-style experiment. Our data eliminate from consideration mechanisms of deviation that posit strengths ~10^4 times Newtonian gravity at…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Chiaverini , S. J. Smullin , A. A. Geraci , D. M. Weld , A. Kapitulnik

In this paper a theoretical model of a magnetic white dwarf is studied. All numerical calculations are performed under the assumption of a spherically symmetric star. The obtained equation of state is stiffer for the increasing value of…

Astrophysics · Physics 2009-11-07 I. Bednarek , A. Brzezina , R. Manka , M. Zastawny-Kubica

The indirect evidence for at least a dozen massive white dwarfs violating the Chandrasekhar mass-limit is considered to be one of the wonderful discoveries in astronomy for more than a decade. Researchers have already proposed a diverse…

General Relativity and Quantum Cosmology · Physics 2021-11-08 Surajit Kalita , T. R. Govindarajan , Banibrata Mukhopadhyay

We are interested on the effects, caused by strong variable density dependent magnetic fields, on hyperonic matter, its symmetry energy, equations of state and mass-radius relations. The inclusion of the anomalous magnetic moment of the…

Nuclear Theory · Physics 2013-07-19 Rudiney Hoffmann Casali , Débora Peres Menezes

Quantum-gravity effects are expected to be suppressed by the Planck mass. For experimental progress it is therefore important to identify potential signatures from Planck-scale physics that are amenable to ultrahigh-precision tests. It is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Lehnert

Several different effects in electroweak quantum corrections are explored separately through the latest data on the weak-boson masses. The leading-log approximation, the improved-Born approximation and the non-decoupling top-quark effects…

High Energy Physics - Phenomenology · Physics 2015-06-25 Zenrō Hioki

The main implications of noncommutativity over astrophysical objects are examined. Noncommutativity is introduced through a deformed dispersion relation $E^{2}=p^{2}c^{2}(1+\lambda E)^{2} + m^{2}c^{4}$ and the relevant thermodynamical…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Orfeu Bertolami , Carlos A. D. Zarro

This document presents a numerical study of the effects of high density nuclear reactions, pycnonuclear reactions, on the evolution of white dwarfs that accrete matter from a companion star. Primarily we seek observable properties that…

High Energy Astrophysical Phenomena · Physics 2020-10-14 Joe Hellmers

This paper aims to provide an introduction to the problem of determining the mass-radius relationship for white dwarfs. Both Newtonian and general relativistic case are examined, electromagnetic interactions are considered and the problem…

High Energy Astrophysical Phenomena · Physics 2020-12-04 Federico Ambrosino

Aims. We investigated the gravitational effects of a scalar field within scalar-tensor gravity as an alternative to dark matter. Motivated by chameleon, symmetron and f(R)-gravity models, we studied a phenomenological scenario where the…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-24 David F. Mota , Vincenzo Salzano , Salvatore Capozziello , Nicola R. Napolitano

We carry out a simple analysis of (n+3)-dimensional gravity in the context of recent work on 'large' supplementary dimensions and deduce a formula for the expected compactification radius for the n additional dimensions in the universe, as…

Nuclear Theory · Physics 2010-11-19 Alejandro Frank , Piet van Isacker , Joaquin Gomez-Camacho