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Related papers: Neutron stars in the bumblebee theory of gravity

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Einstein-bumblebee gravity, as a class of massive non-minimally coupled vector-tensor theories, provides a useful framework for constraining Lorentz symmetry breaking through astrophysical observations, largely due to the existence of exact…

General Relativity and Quantum Cosmology · Physics 2026-03-23 Zhe Luo , Shoulong Li , Hongwei Yu

In this work, we study a vector model of spontaneous spacetime-symmetry breaking coupled to gravity: the bumblebee model. The primary focus is on static spherically symmetric solutions. Complementing previous work on black hole solutions,…

General Relativity and Quantum Cosmology · Physics 2025-12-02 Quentin G. Bailey , Hailey S. Murray , Dario T. Walter-Cardona

We investigate the static spherically symmetric vacuum solutions in a generalized bumblebee gravity model characterized by non-minimal couplings $B^2 R$ and $B^\mu B^\nu R_{\mu\nu}$. We demonstrate that the variation of the action and the…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Jie Zhu , Hao Li

The bumblebee gravity model is a vector-tensor theory of gravitation where the vector field nonminimally couples to the Ricci tensor. By investigating the vacuum field equations with spherical symmetry, we find two families of black-hole…

General Relativity and Quantum Cosmology · Physics 2023-01-16 Rui Xu , Dicong Liang , Lijing Shao

We report the existence of novel static spherical black-hole solutions in a vector-tensor gravitational theory called the bumblebee gravity model which extends the Einstein-Maxwell theory by allowing the vector to nonminimally couple to the…

General Relativity and Quantum Cosmology · Physics 2023-03-20 Rui Xu , Dicong Liang , Lijing Shao

We numerically construct compact stars in the scalar-tensor theory of gravity with non-minimal derivative coupling of a scalar field to the curvature and nonzero cosmological constant. There are two free parameters in this model of gravity:…

General Relativity and Quantum Cosmology · Physics 2025-04-08 P. E. Kashargin , A. A. Lebedev , S. V. Sushkov

In theories where the Lorentz symmetry of gravity is spontaneously broken, a non-minimally coupled bumblebee vector field acquires a nonzero vacuum expectation value, leading to modifications of standard General Relativity (GR). In this…

General Relativity and Quantum Cosmology · Physics 2026-03-11 Faizuddin Ahmed , Shubham Kala , Ahmad Al-Badawi

The bumblebee field coupled with gravity is considered. This gravitational theory exhibits spontaneous breaking of Lorentz symmetry. The G\"{o}del-type universe is introduced and then the causality and its violation are studied. Causal and…

General Relativity and Quantum Cosmology · Physics 2020-05-20 W. D. R. Jesus , A. F. Santos

The static spherical vacuum solution in a bumblebee gravity model where the bumblebee field $B_\mu$ has a two-component space-like, light-like, and time-like vacuum expectation value $b_\mu$ is studied. Based on the results, we present a…

General Relativity and Quantum Cosmology · Physics 2026-04-06 Jie Zhu , Hao Li

Vector theories with spontaneous Lorentz violation, known as bumblebee models, are examined in flat spacetime using a Hamiltonian constraint analysis. In some of these models, Nambu-Goldstone modes appear with properties similar to photons…

High Energy Physics - Theory · Physics 2014-11-18 Robert Bluhm , Nolan L. Gagne , Robertus Potting , Arturs Vrublevskis

We study the vacuum solutions of a gravity model where Lorentz symmetry is spontaneously broken once a vector field acquires a vacuum expectation value. Results are presented for the purely radial Lorentz symmetry breaking (LSB),…

High Energy Physics - Theory · Physics 2009-11-11 O. Bertolami , J. Paramos

In this paper, we investigate the properties of relativistic stars made of isotropic matter within the framework of the minimal Standard Model Extension, where a Bumblebee field (BF) coupled to spacetime induces spontaneous Lorentz symmetry…

General Relativity and Quantum Cosmology · Physics 2025-05-15 Grigoris Panotopoulos , Ali Övgün

We study static, spherically symmetric neutron stars in a class of scalar-tensor theories with non-canonical kinetic terms (K-essence) obeying all causality and hyperbolicity conditions. These models have non-trivial dynamics that lead to a…

General Relativity and Quantum Cosmology · Physics 2025-09-12 Mark P. Hertzberg , Oleksandr S. Stashko

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

In this paper, we find Kerr solution accompanied with a nontrivial vector field as a solution to one of the simplest vector-tensor theories of gravity, namely the bumblebee model with an intriguing coupling constant between the Ricci…

General Relativity and Quantum Cosmology · Physics 2026-03-31 Rui Xu , Zhan-Feng Mai , Dicong Liang

Neutron stars are natural laboratories for testing gravity in the strong field regime. That is why the full spectrum of neutron star solutions in different modified theories should be thoroughly studied. Among the most natural modifications…

General Relativity and Quantum Cosmology · Physics 2024-10-17 Kalin V. Staykov , Peter Y. Yordanov , Daniela D. Doneva , Stoytcho S. Yazadjiev

In this study, we found a new traversable wormhole solution in the framework of a bumblebee gravity model. With these types of models, the Lorentz symmetry violation arises from the dynamics of a bumblebee vector field that is non-minimally…

General Relativity and Quantum Cosmology · Physics 2019-01-30 Ali Övgün , Kimet Jusufi , İzzet Sakallı

Scalar-tensor theories of gravity are natural phenomenological alternatives to General Relativity, where the gravitational interaction is mediated by a scalar degree of freedom, besides the usual tensor gravitons. In regions of the…

General Relativity and Quantum Cosmology · Physics 2013-04-29 Enrico Barausse , Carlos Palenzuela , Marcelo Ponce , Luis Lehner

By keeping the cosmological principle i.e., an isotropic and homogeneous universe, we consider the cosmology of a vector-tensor theory of gravitation known as the \textit{bumblebee} model. In this model a single Lorentz-violating timelike…

General Relativity and Quantum Cosmology · Physics 2023-05-11 Mohsen Khodadi , Gaetano Lambiase , Ahmad Sheykhi

Lorentz-Violating (LV) scenario gets involved through a bumblebee field vector field $B_\mu$. A spontaneous symmetry breaking allows the field to acquires a vacuum expectation value that generates LV into the system. A Kerr-Sen-like…

General Relativity and Quantum Cosmology · Physics 2021-05-11 Sohan Kumar Jha , Anisur Rahaman
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