English
Related papers

Related papers: Noncommutative effects in astrophysical objects: a…

200 papers

A scalar-tensor theory of gravity is formulated in which $G$ and particle masses are allowed to vary. The theory yields a globally static cosmological model with no evolutionary timescales, no cosmological coincidences, and no flatness and…

General Physics · Physics 2015-10-01 Meir Shimon

The purpose of this paper is to analyze the stability of interacting matter in the presence of a cosmological constant. Using an approach based on the heat equation, no imaginary part is found for the effective potential in the presence of…

High Energy Physics - Theory · Physics 2014-11-20 Enrique Álvarez , Roberto Vidal

We study in detail the effect of quantum decoherence in neutrino oscillations. We adopt a phenomenological approach that allows us to parametrize the energy dependence of the decoherence effects resulting from the modification of the…

High Energy Physics - Phenomenology · Physics 2025-12-11 Bikash Kumar Acharya , Indra Kumar Banerjee , Ujjal Kumar Dey

In this work we study the effects of the non-gravitational exchange energy (Q) between dark matter (DM) fluid and dark energy (DE) fluid on the background evolution of the cosmological parameters. A varying equation of state (EOS)…

General Relativity and Quantum Cosmology · Physics 2015-04-21 Freddy Cueva Solano

We present a formulation in a curved background of noncommutative mechanics, where the object of noncommutativity $\theta^{\mu\nu}$ is considered as an independent quantity having a canonical conjugate momentum. We introduced a…

High Energy Physics - Theory · Physics 2011-04-05 E. M. C. Abreu , R. Amorim , W. Guzmán Ramírez

We use cosmological perturbation theory to study the backreaction effects of a self-consistent and well-defined cosmological averaging on the dynamics and the evolution of the Universe. Working with a perturbed…

General Relativity and Quantum Cosmology · Physics 2013-10-30 Iain A. Brown , Alan A. Coley , D. Leigh Herman , Joey Latta

Rotation has a number of important effects on the evolution of stars. Apart from structural changes because of the centrifugal force, turbulent mixing and meridional circulation caused by rotation can dramatically affect a star's chemical…

Solar and Stellar Astrophysics · Physics 2015-06-04 Adrian T. Potter , Christopher A. Tout , Ines Brott

We study some aspects when one consider the existence of one extra-dimension in addition to a non-commutative space-time. We present here two different examples, where the first one provides a scenario were it is possible to relate the…

High Energy Physics - Theory · Physics 2019-02-05 M. Dias

In this review we discuss the global geometry of noncommutative field theories from a deformation point of view: The space-times under consideration are deformations of classical space-time manifolds using star products. Then matter fields…

Quantum Algebra · Mathematics 2007-10-12 Stefan Waldmann

This paper reviews results about discrete physics and non-commutative worlds and explores further the structure and consequences of constraints linking classical calculus and discrete calculus formulated via commutators. In particular we…

Mathematical Physics · Physics 2018-06-12 Louis H. Kauffman

We derive non-flat cosmological models for two cases (i.e., dust and radiation) in the context of M{\o}ller's tetradic theory (MTT) of gravitation using the tetrad that creates the non-flat Friedmann-Robertson-Walker (FRW) metric. These two…

General Relativity and Quantum Cosmology · Physics 2022-04-21 G. G. L. Nashed , A. T. Shafeek

Stabilization, by deformation, of the Poincar\'{e}-Heisenberg algebra requires both the introduction of a fundamental lentgh and the noncommutativity of translations which is associated to the gravitational field. The noncommutative…

Mathematical Physics · Physics 2017-11-02 R. Vilela Mendes

There are many factors that contribute to the breaking of the spherical symmetry of a neutron star. Most notably is rotation, magnetic fields, and/or accretion of matter from companion stars. All these phenomena influence the macroscopic…

High Energy Astrophysical Phenomena · Physics 2012-05-31 Rodrigo Negreiros , Stefan Schramm , Fridolin Weber

Considering space--time to be non-commutative, we study the evolution of the universe employing the approach of Newtonian cosmology. Generalizing the conservation of energy and the first law of thermodynamics to $\kappa$-deformed…

General Relativity and Quantum Cosmology · Physics 2023-07-31 E. Harikumar , Harsha Sreekumar , Suman Kumar Panja

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…

General Relativity and Quantum Cosmology · Physics 2019-01-08 Arun Mathew , Malay Kumar Nandy

This is a brief review where some basic elements of non-commutative geometry are given. The rules and ingredients that enter in the construction of the standard model and grand unification models in non-commutative geometry are summarized.…

High Energy Physics - Theory · Physics 2015-03-10 A. H. Chamseddine

Many extensions of the Standard Model predict large numbers of additional unstable particles whose decays in the early universe are tightly constrained by observational data. For example, the decays of such particles can alter the ratios of…

High Energy Physics - Phenomenology · Physics 2019-02-20 Keith R. Dienes , Jason Kumar , Patrick Stengel , Brooks Thomas

Since the geometry of our universe seems to depend very little on baryonic matter, we consider a variational principle involving only dark matter and dark energy which in addition make them depend on each other. There are no adjustable…

General Relativity and Quantum Cosmology · Physics 2013-11-19 Joseph Katz

Noncommutativity of the spacetime coordinates has been explored in several contexts, mostly associated to phenomena at the Planck length scale. However, approaching this question through deformation theory and the principle of stability of…

High Energy Physics - Theory · Physics 2019-06-19 R. Vilela Mendes

We investigate the impact of spacetime non-commutativity on the tidal deformability of compact objects and explore the feasibility of detecting non-commutative (NC) effects through gravitational wave (GW) observations. We considered NC…

General Relativity and Quantum Cosmology · Physics 2025-05-02 Junting Peng , Yanbo Zhao , Antonino Marciano