English
Related papers

Related papers: Constraining fundamental parameters in modified gr…

200 papers

We explore the potential variation of two fundamental constants, the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu$, within the framework of modified gravity theories and finite-temperature effects. Utilising…

Solar and Stellar Astrophysics · Physics 2025-09-17 Akhil Uniyal , Surajit Kalita , Yosuke Mizuno , Sayan Chakrabarti , Yan Lu

Modified gravity theories can introduce modifications to the Poisson equation in the Newtonian limit. As a result, we expect to see interesting features of these modifications inside stellar objects. White dwarf stars are one of the most…

General Relativity and Quantum Cosmology · Physics 2017-10-06 Srimanta Banerjee , Swapnil Shankar , Tejinder P. Singh

Fundamental constants are crucial for comprehending physical mechanisms, but their measurements contain uncertainties due to experimental limitations. We investigate the impact of system temperature on these uncertainties using nearby white…

Solar and Stellar Astrophysics · Physics 2023-11-02 Akhil Uniyal , Surajit Kalita , Sayan Chakrabarti

Theories that attempt to unify the four fundamental interactions and alternative theories of gravity predict time and/or spatial variation of the fundamental constants of nature. Different versions of these theories predict different…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Susana J. Landau

This article describes the various experimental bounds on the variation of the fundamental constants of nature. After a discussion on the role of fundamental constants, of their definition and link with metrology, the various constraints on…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jean-Philippe Uzan

In this paper, we investigate how the fine structure constant, $\alpha$, locally varies in the presence of a static and spherically symmetric gravitational source. The procedure consists in calculating the solution and the energy…

General Relativity and Quantum Cosmology · Physics 2016-09-27 V. B. Bezerra , M. S. Cunha , C. R. Muniz , M. O. Tahim , H. S. Vieira

We explore the internal structures of the white dwarfs in two different modified theories of gravity: (i) scalar-tensor-vector gravity and (ii) beyond Horndeski theories of $G_3$ type. The modification of the gravitational force inside the…

General Relativity and Quantum Cosmology · Physics 2023-01-31 Khursid Alam , Tousif Islam

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…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 D. M. N. Magano , J. M. A. Vilas Boas , C. J. A. P. Martins

The possibility of variations of the values of fundamental constants is a phenomenon predicted by a number of scenarios beyond General Relativity. This can happen if ``our'' fundamental constants are not the actual constants of the…

General Relativity and Quantum Cosmology · Physics 2024-07-12 Cosimo Bambi

White dwarfs (WDs), as the remnants of low to intermediate-mass stars, provide a unique opportunity to explore the interplay between quantum mechanical degeneracy pressure and gravitational forces under extreme conditions. In this study, we…

General Relativity and Quantum Cosmology · Physics 2025-05-22 Juan M. Z. Pretel , Takol Tangphati , İzzet Sakallı , Ayan Banerjee

We use the most recent, complete and independent measurements of masses and radii of white dwarfs in binaries to bound the class of non-trivial modified gravity theories, viable after GW170817/GRB170817, using its effect on the mass-radius…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Ippocratis D. Saltas , Ignacy Sawicki , Ilidio Lopes

The possibility of variation of the fundamental constants of nature has been a long-standing question, with important consequences for fundamental physics and cosmology. In particular, it has been shown that variations in the fine-structure…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 Rodrigo S. Gonçalves , Susana Landau , Jailson S. Alcaniz , Rodrigo F. L. Holanda

Low energy imprints of modifications to general relativity are often found in pressure balance equations inside stars. These modifications are then amenable to tests via astrophysical phenomena, using observational effects in stellar…

General Relativity and Quantum Cosmology · Physics 2023-07-07 Debojyoti Garain , Pritam Banerjee , Shaswata Chowdhury , Tapobrata Sarkar

The Standard Model of particle physics and the theory of General Relativity (GR) currently provide a good description of almost all phenomena of particle physics and gravitation that have received controlled experimental tests. However, the…

Atomic Physics · Physics 2009-01-23 Thomas Dent

It is well known that alternative theories to the Standard Model allow -- and sometimes require -- fundamental constants, such as the fine-structure constant, $\alpha$, to vary in spacetime. We demonstrate that one way to investigate these…

High Energy Physics - Phenomenology · Physics 2025-03-17 E. -A. Kolonia , C. J. A. P. Martins , Konstantinos N. Gourgouliatos

Super-Chandrasekhar white dwarfs are a timely topic in the last years in the scientific community due to its connection to supernovae type Ia (SN Ia). Some early studies tackled the possibility of white dwarfs surpassing the Chandrasekhar…

General Relativity and Quantum Cosmology · Physics 2025-10-20 Ronaldo V. Lobato , Geanderson A. Carvalho , Neelima G. Kelkar , Marek Nowakowski

Several recent studies have shown that very wide binary stars can potentially provide an interesting test for modified-gravity theories which attempt to emulate dark matter; these systems should be almost Newtonian according to standard…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Charalambos Pittordis , Will Sutherland

Recently, white dwarf stars have found a new use in the fundamental physics community. Many prospective theories of the fundamental interactions of Nature allow traditional constants, like the fine structure constant $\alpha$, to vary in…

Solar and Stellar Astrophysics · Physics 2014-10-14 S. P. Preval , M. A. Barstow , J. B. Holberg , J. D. Barrow , J. C. Berengut , J. K. Webb , D. Dougan , J. Hu

The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravitational interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong…

General Relativity and Quantum Cosmology · Physics 2020-09-15 Gonzalo J. Olmo , Diego Rubiera-Garcia , Aneta Wojnar

The standard LambdaCDM model based on General Relativity (GR) including cold dark matter (CDM) is very successful at fitting cosmological observations, but recent non-detections of candidate dark matter (DM) particles mean that various…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-09 Charalambos Pittordis , Will Sutherland
‹ Prev 1 2 3 10 Next ›