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Related papers: Quantum Gravity Effects around Sagittarius A*

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The detection of quantum gravity effects is highly limited in both macroscopic and microscopic scenarios: The small quantum parameter makes most large-scale observations practically indistinguishable from general relativity. While at the…

General Relativity and Quantum Cosmology · Physics 2025-09-10 Haida Li , Xiangdong Zhang

Various contenders for a complete theory of quantum gravity are at odds with each other. This is in particular seen in the ways they relate to information and black holes, and how to effectively treat quantization of the background…

High Energy Physics - Theory · Physics 2016-09-08 Gerard 't Hooft , Steven B. Giddings , Carlo Rovelli , Piero Nicolini , Jonas Mureika , Matthias Kaminski , Marcus Bleicher

Near-IR and X-ray flares have been detected from the supermassive black hole Sgr A* at the center of our Galaxy with a (quasi)-period of ~17-20 minutes, suggesting an emission region only a few Schwarzschild radii above the event horizon.…

We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A* taken with the Event Horizon Telescope in 2017 April at a wavelength of 1.3 mm. Imaging of Sgr A* has been conducted through surveys over a wide range of…

High Energy Astrophysical Phenomena · Physics 2023-11-17 The Event Horizon Telescope Collaboration

Recently, a study on shadow of quantum corrected Schwarzschild black hole in loop quantum gravity appeared in [Ye et al., Phys. Lett. B 851, 138566, (2024)] assuming a fixed value of Barbero-Immirzi parameter $\gamma$. Following this…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Muhammad Ali Raza , M. Zubair , Farruh Atamurotov , Ahmadjon Abdujabbarov

Quadratic gravity constitutes a prototypical example of a perturbatively renormalizable quantum theory of the gravitational interactions. In this work, we construct the associated phase space of static, spherically symmetric, and…

General Relativity and Quantum Cosmology · Physics 2023-05-10 Jesse Daas , Kolja Kuijpers , Frank Saueressig , Michael F. Wondrak , Heino Falcke

In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size…

We show that a possible astrophysical experiment, detection of lensed images of stars orbiting close to Sgr A*, can provide insight into the form of the metric around a black hole. We model Sgr A* as a black hole and add in a…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Amitai Y. Bin-Nun

The visible universe is filled with different types of plasma media in the form of stars, nebulas and other forms of excited gases. These matter fields have a high influence on the gravity and are likely to be present around the black holes…

General Relativity and Quantum Cosmology · Physics 2024-05-13 Muhammad Ali Raza , M. Zubair , Eiman Maqsood

In the neighborhood of Sgr A*, several stars (S2, S12, S14, S1, S8, S13) enjoy an accurate determination of their orbital parameters. General Relativity predicts that the central black hole acts as a gravitational lens on these stars,…

Astrophysics · Physics 2009-11-10 V. Bozza , L. Mancini

The black hole in the center of the Milky Way has been observed and modeled intensely during the last decades. It is also the prime target of a number of new experiments that aim to zoom into the vicinity of its horizon and reveal the inner…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Dimitrios Psaltis , Tim Johannsen

Quantum information transfer necessary to reconcile black hole evaporation with quantum mechanics, while approximately preserving regular near-horizon geometry, can be simply parameterized in terms of couplings of the black hole internal…

High Energy Physics - Theory · Physics 2014-12-17 Steven B. Giddings

This work is devoted to investigate some consequences of black holes physics beyond the domain of general relativity, mainly in effective extra dimensional models. The investigation is carried along three gravitational effects, namely the…

General Relativity and Quantum Cosmology · Physics 2019-02-28 Rogerio Teixeira Cavalcanti

We examine the Schwarzschild interior of a black hole, incorporating quantum gravitational modifications due to loop quantum gravity. We consider an improved loop quantization using techniques that have proven successful in loop quantum…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian G. Boehmer , Kevin Vandersloot

The rotating loop quantum gravity black hole is a newly proposed non-singular black hole, which eliminates spacetime singularities when a regularization parameter is introduced through loop quantum corrections. This parameter is expected to…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Zhong-Wu Xia , Hao Yang , Yan-Gang Miao

A gravitational theory is formulated by considering the physical processes underlying relativistic dilation of time and contraction of space. It is shown that the point mass solution of general relativity's field equation - the…

General Relativity and Quantum Cosmology · Physics 2015-08-25 James W. Douglass

Explicit tests are presented of the conjectured entropic origin of the gravitational force. The gravitational force on a test particle in the vicinity of the horizon of a large Schwarzschild black hole in arbitrary spacetime dimensions is…

General Relativity and Quantum Cosmology · Physics 2018-08-08 Sourav Bhattacharya , Panagiotis Charalambous , Theodore N Tomaras , Nicolaos Toumbas

The interest in the implications that astrophysical observations have for the understanding of the structure of black holes has grown since the first detection of gravitational waves. Many arguments that are put forward in order to…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Anna Zulianello , Raúl Carballo-Rubio , Stefano Liberati , Stefano Ansoldi

Several works over the past years have discussed the possibility of testing fundamental physics using Very Long Baseline Interferometry horizon-scale black hole (BH) images, such as the Event Horizon Telescope (EHT) images of M87$^*$ and…

Astrophysics of Galaxies · Physics 2022-05-31 Sunny Vagnozzi , Luca Visinelli

The Event Horizon Telescope (EHT) will soon provide the first high-resolution images of the Galactic Centre supermassive black hole (SMBH) candidate Sagittarius A* (Sgr A*), enabling us to probe gravity in the strong-field regime. Besides…

High Energy Astrophysical Phenomena · Physics 2021-05-26 C. M. Fromm , Y. Mizuno , Z. Younsi , H. Olivares , O. Porth , M. De Laurentis , H. Falcke , M. Kramer , L. Rezzolla
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