English
Related papers

Related papers: Relativistic stars in mass-varying massive gravity

200 papers

In this paper we study the phenomenology of stars and galaxies in massive bigravity. We give parameter conditions for the existence of viable star solutions when the radius of the star is much smaller than the Compton wavelength of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-07 Jonas Enander , Edvard Mortsell

Neutron stars are highly compact astrophysical objects and therefore of utmost relevance to learn about theories of gravity. Whereas the proper equation of state of the nuclear matter inside neutron stars is not yet known, and a wide range…

General Relativity and Quantum Cosmology · Physics 2022-04-28 Jutta Kunz

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

General properties of neutron stars are briefly reviewed with an emphasis on the indispensability of general relativity in our understanding of these fascinating objects. In Newtonian gravity the pressure within a star merely plays the role…

High Energy Astrophysical Phenomena · Physics 2017-03-02 K. Yavuz Ekşi

We study relativistic stars in the simplest model of the de Rham-Gabadadze-Tolley massive gravity which describes the massive graviton without ghost propagating mode. We consider the hydrostatic equilibrium, and obtain the modified…

General Relativity and Quantum Cosmology · Physics 2016-06-15 Taishi Katsuragawa , Shin'ichi Nojiri , Sergei D. Odintsov , Masashi Yamazaki

We investigate relativistic star solutions in Mass-Varying Massive Gravity (MVMG) with a diagonal metric. Contrary to the intuition that there is no fundamental difference between diagonal metric and non-diagonal metric solutions regarding…

General Relativity and Quantum Cosmology · Physics 2023-04-20 De-Jun Wu

The mass of the graviton, if nonzero, is usually considered to be very small, e.g. of the Hubble scale, from several observational constraints. In this paper, we propose a gravity model where the graviton mass is very small in the usual…

General Relativity and Quantum Cosmology · Physics 2022-04-22 Jun Zhang , Shuang-Yong Zhou

$f(R)$ theories of gravity are one of the most popular alternative explanations for dark energy and therefore studying the possible astrophysical implications of these theories is an important task. In the present paper we make a…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas

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

We consider the mass-radius bounds for spherically symmetric static compact objects in the de Rham-Gabadadze-Tolley (dRGT) Massive Gravity theories, free of ghosts. In this type of gravitational theories the graviton, the quantum of…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Parinya Kareeso , Piyabut Burikham , Tiberiu Harko

We study slowly-rotating neutron stars in ghost-free massive bigravity. This theory modifies General Relativity by introducing a second, auxiliary but dynamical tensor field that couples to matter through the physical metric tensor through…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Andrew Sullivan , Nicolas Yunes

In the context of f(R) gravity theories, we show that the apparent mass of a neutron star as seen from an observer at infinity is numerically calculable but requires careful matching, first at the star's edge, between interior and exterior…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Miguel Aparicio Resco , Alvaro de la Cruz-Dombriz , Felipe J. Llanes-Estrada , Victor Zapatero Castrillo

The masses and radii of neutron stars are discussed in general relativity and scalar-tensor theory of gravity and the differences are compared with the current uncertainties stemming from the nuclear equation of state in the relativistic…

General Relativity and Quantum Cosmology · Physics 2019-07-16 F. J. Fattoyev

We develop a theoretical framework to study slowly rotating compact stars in a rather general class of alternative theories of gravity, with the ultimate goal of investigating constraints on alternative theories from electromagnetic and…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Paolo Pani , Emanuele Berti , Vitor Cardoso , Jocelyn Read

Several attempts to construct theories of gravity with variable mass are considered. The theoretical impacts of allowing the rest mass to vary with respect to time or an appropriate curve parameter are examined in the framework of Newtonian…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Leclerc

In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas

Generically, massive gravity gives a non-unique gravitational field around a star. For a special family of massive gravity theories, we show that the stellar gravitational field is unique and observationally acceptable, that is close to…

High Energy Physics - Theory · Physics 2015-05-28 Andrei Gruzinov , Mehrdad Mirbabayi

We investigate realistic models of compact objects, focusing on neutron and strange stars, composed by dense matter and dark energy in the form of a simple fluid or scalar field interacting with matter. For the dark energy component, we use…

General Relativity and Quantum Cosmology · Physics 2023-08-01 Artyom V. Astashenok , Sergey D. Odintsov , Vasilis K. Oikonomou

We study the impact of non-local modifications of General Relativity on stellar structure. In particular, assuming an analytic distortion function and specific equations of state, we made use of remnant stars to put qualitative constraints…

General Relativity and Quantum Cosmology · Physics 2023-01-23 Grigoris Panotopoulos , Javier Rubio , Ilídio Lopes

In this work, we investigate the equilibrium configurations of massive white dwarfs (MWD) in the context of modified gravity, namely $f(R,L_m)$ gravity, where $R$ stands for the Ricci scalar and $L_m$ is the Lagrangian matter density. We…

General Relativity and Quantum Cosmology · Physics 2022-06-22 R. V. Lobato , G. A. Carvalho , N. G. Kelkar , M. Nowakowski
‹ Prev 1 2 3 10 Next ›