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Related papers: Superradiance in Modified Gravity (MOG)

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A covariant modified gravity (MOG) is formulated by adding to general relativity two new degrees of freedom, a scalar field gravitational coupling strength $G= 1/\chi$ and a gravitational spin 1 vector field $\phi_\mu$. The $G$ is written…

General Relativity and Quantum Cosmology · Physics 2021-02-17 J. W. Moffat

Scalar-tensor-vector gravity, also known as modified gravity (MOG), has emerged as an alternative to General Relativity (GR). It aims to explain astrophysical phenomena without invoking dark matter. The S-stars orbiting the supermassive…

General Relativity and Quantum Cosmology · Physics 2026-05-21 Ioannis Liodis , Gernot Heissel , Rita Mastroioanni , Jai Grover , Dario Izzo

The astrophysical consequences of the presence of a quintessence scalar field on the evolution of the horizon and on the accretion disk surrounding a static black hole, in the Scalar-Vector-Tensor version of Modified Gravity (MOG), are…

General Relativity and Quantum Cosmology · Physics 2023-09-15 Haidar Sheikhahmadi , Saheb Soroushfar , S. N. Sajadi , Tiberiu Harko

As an alternative to dark matter models, MOdified Gravity (MOG) theory can compensate for dark matter by a covariant modification of Einstein gravity. The theory introduces two additional scalar fields and one vector field. The aim is to…

Astrophysics of Galaxies · Physics 2015-06-16 J. W. Moffat , S. Rahvar

Rotating black holes are well known to amplify the perturbing bosonic fields in certain parameter spaces. This phenomenon is popularly known as superradiance. In addition to rotation in the spacetime, charge plays a crucial role in the…

General Relativity and Quantum Cosmology · Physics 2025-04-02 Rajesh Karmakar

The Quasinormal modes (QNMs) for gravitational and electromagnetic perturbations are calculated in a Scalar-Tensor-Vector (Modified Gravity) spacetime, which was initially proposed to obtain correct dynamics of galaxies and galaxy clusters…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Luciano Manfredi , Jonas Mureika , John Moffat

We analyze the thermodynamical properties of black holes in a modified theory of gravity, which was initially proposed to obtain correct dynamics of galaxies and galaxy clusters without dark matter. The thermodynamics of non-rotating and…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Jonas R. Mureika , John W. Moffat , Mir Faizal

The polarized images of a synchrotron emitting ring are studied in the spacetime of a rotating black hole in the Scalar-Tensor-Vector-Gravity (STVG) theory. The black hole owns an additional dimensionless MOG parameter described its…

General Relativity and Quantum Cosmology · Physics 2022-10-26 Xin Qin , Songbai Chen , Zelin Zhang , Jiliang Jing

We examine the accretion of matter onto a black hole in scalar--tensor--vector gravity (STVG) also known as modified gravity (MOG). The gravitational constant is $G=G_{N} (1 + \alpha)$ where $\alpha$ is a parameter taken to be constant for…

General Relativity and Quantum Cosmology · Physics 2019-11-11 Anslyn J. John

In rotating black hole background surrounded by dark matter, we investigated the super-radiant phenomenon of massive scalar field and its associated instability.Using the method of asymptotic matching, we computed the amplification factor…

General Relativity and Quantum Cosmology · Physics 2025-03-06 Quan-Xu Liu , Ya-Peng Hu , Tao-Tao Sui , Yu-Sen An

The field equations for Scalar-Tensor-Vector-Gravity (STVG) or modified gravity (MOG) have a static, spherically symmetric black hole solution determined by the mass $M$ with two horizons. The strength of the gravitational constant is…

General Relativity and Quantum Cosmology · Physics 2015-05-05 J. W. Moffat

This paper aims to investigate the scattering of fermions by spherically symmetric MOG black holes, which are a type of black holes encountered in scalar-tensor-vector modified gravitational theories. After determining the scattering modes…

General Relativity and Quantum Cosmology · Physics 2020-02-27 Ciprian A. Sporea

Our modified gravity theory (MOG) is a gravitational theory without exotic dark matter, based on an action principle. MOG has been used successfully to model astrophysical phenomena such as galaxy rotation curves, galaxy cluster masses, and…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-25 J. W. Moffat , V. T. Toth

A regular rotating MOG (modified gravity) compact object is derived that reduces to the Kerr black hole when the parameter $\alpha=0$. Physical consequences of the dark compact object, which is regular everywhere in spacetime for $\alpha >…

General Relativity and Quantum Cosmology · Physics 2021-02-15 J. W. Moffat

Black holes provide a natural laboratory to study particle physics and astrophysics. When black holes are surrounded by matter fields, there will be plenty of phenomena which can have observational consequences, from which we can learn…

General Relativity and Quantum Cosmology · Physics 2023-02-22 Zhen Li

The scalar-tensor-vector gravity (STVG) theory has attracted significant interest due to its ability to effectively address the issue of galaxy rotation curves and clusters of galaxies without considering the influence of dark matter. In…

General Relativity and Quantum Cosmology · Physics 2024-09-04 Wentao Liu , Di Wu , Xiongjun Fang , Jiliang Jing , Jieci Wang

We consider the cosmological consequences of a special scalar-tensor-vector theory of gravity, known as MOG (for MOdified Gravity), proposed to address the dark matter problem. This theory introduces two scalar fields $G(x)$ and $\mu(x)$,…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Sara Jamali , Mahmood Roshan , Luca Amendola

Black hole superradiance provides a window into the dynamics of light scalar fields and their interactions close to a rotating black hole. Due to the rotation of the black hole, the amplitude of the scalar field becomes magnified, leading…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Stephon Alexander , Gregory Gabadadze , Leah Jenks , Nicolás Yunes

In this paper, we present a black hole solution with a cosmological constant in the Scalar-Tensor-Vector Modified Gravity (MOG) theory, where the strength of the gravitational constant is determined by $G = G_\text{N}(1+\alpha)$. We derive…

General Relativity and Quantum Cosmology · Physics 2024-02-22 Wentao Liu , Xiongjun Fang , Jiliang Jing , Jieci Wang

The paper has explored analogue of gravitational synchrotron massive particle and Penrose process in MOdified Gravity (MOG) known as Scalar-Tensor-Vector-Gravity (STVG). Investigation of the gravitational field around Kerr-MOG black hole…

General Relativity and Quantum Cosmology · Physics 2023-06-30 Bobur Turimov , Husan Alibekov , Pulat Tadjimuratov , Ahmadjon Abdujabbarov
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