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Related papers: Testing the No-Hair Theorem with Sgr A*

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Motivated by the study of holographic superconductors, we generalize no-hair theorems for minimally coupled scalar fields charged under an Abelian gauge field, in arbitrary dimensions and with arbitrary horizon topology. We first present a…

High Energy Physics - Theory · Physics 2009-11-18 Juan Fernandez-Gracia , Bartomeu Fiol

Several hairy black hole solutions are known to violate the original version of the celebrated no-hair conjecture. This prompted the development of a new theorem that establishes a universal lower bound on the extension of hairs outside any…

General Relativity and Quantum Cosmology · Physics 2024-06-14 Rajes Ghosh , Selim Sk , Sudipta Sarkar

One avenue for testing the no-hair theorem is obtained through timing a pulsar orbiting close to a black hole and fitting for quadrupolar effects on the time-of-arrival of pulses. If deviations from the Kerr quadrupole are measured, then…

General Relativity and Quantum Cosmology · Physics 2015-11-09 Pierre Christian , Dimitrios Psaltis , Abraham Loeb

Measuring the astrometric and spectroscopic data of stars orbiting the central black hole in our galaxy (Sgr A*) offers a promising way to measure relativistic effects. In principle, the "no-hair" theorem can be tested at the Galactic…

Astrophysics of Galaxies · Physics 2026-03-11 K. Abd El Dayem , F. H. Vincent , G. Heissel , T. Paumard , G. Perrin

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

Thanks to the release of the extraordinary EHT image of shadow attributed to the M87* supermassive black hole (SMBH), we have a novel window to assess the validity of fundamental physics in the strong-field regime. Motivated by this, we…

General Relativity and Quantum Cosmology · Physics 2021-09-22 Mohsen Khodadi , Gaetano Lambiase , David F. Mota

In the realm of spacetimes governed by Einstein's general relativity and containing only Maxwell's electromagnetic field, stationary black holes are fully characterized by their mass, electric or magnetic charge, and angular momentum -- a…

General Relativity and Quantum Cosmology · Physics 2024-10-18 Romain Gervalle

Recently, one of my articles presented intriguing findings on the superradiant stability of Kerr black holes. These findings drew conclusions that appear to challenge the established ``No Hair Theorem". As is widely known, the ``No Hair…

General Physics · Physics 2023-08-29 Wen-Xiang Chen , Yao-Guang Zheng

According to the no-hair theorem, astrophysical black holes are uniquely characterized by their masses and spins and are described by the Kerr metric. Several parametric spacetimes which deviate from the Kerr metric have been proposed in…

General Relativity and Quantum Cosmology · Physics 2015-12-16 Tim Johannsen

According to the no-hair theorem, static black holes are described by a Schwarzschild spacetime provided there are no other sources of the gravitational field. This requirement, however, is in astrophysical realistic scenarios often…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Norman Gürlebeck

Within 5-10 years, very-long baseline interferometry (VLBI) facilities will be able to directly image the accretion flow around SgrA$^*$, the super-massive black hole candidate at the center of the Galaxy, and observe the black hole…

General Relativity and Quantum Cosmology · Physics 2014-06-19 Naoki Tsukamoto , Zilong Li , Cosimo Bambi

No-hair theorems are uniqueness results constraining the form of the metric of black holes in general relativity. These theorems are typically formulated under idealized assumptions, involving a mixture of local (regularity of the horizon)…

General Relativity and Quantum Cosmology · Physics 2025-08-19 Carlos Barceló , Raúl Carballo-Rubio , Luis J. Garay , Gerardo García-Moreno

We examine the ability to test the black hole no-hair theorem at the 10% level in this decade using the binary black hole in OJ287. In the test we constrain the value of the dimensionless parameter q that relates the scaled quadrupole…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 M. J. Valtonen , S. Mikkola , H. J. Lehto , A. Gopakumar , R. Hudec , J. Polednikova

In this paper, we investigate the optical appearance of a regular static spherically symmetric hairy black hole within the context of Minkowski deformation governed by the parameter \(\alpha\). This black hole describes a hairy black hole…

General Relativity and Quantum Cosmology · Physics 2024-08-23 Xilong Yang , Meirong Tang , Zhaoyi Xu

Recently the Event Horizon Telescope Collaboration, with very-long baseline interferometric observations, resolved structure at the scale of $\sim5$ Schwarzschild radii about the center of M87$^*$, the supermassive black hole resident at…

General Relativity and Quantum Cosmology · Physics 2021-05-24 Zack Carson , Kent Yagi

The continuum-fitting and the iron line methods are leading techniques capable of probing the spacetime geometry around astrophysical black hole candidates and testing the no-hair theorem. In the present paper, we review the two approaches,…

General Relativity and Quantum Cosmology · Physics 2016-02-25 Cosimo Bambi , Jiachen Jiang , James F. Steiner

In this study, we explore the possibility of testing the no-hair theorem with gravitational waves from massive black hole binaries in the frequency band of the Laser Interferometer Space Antenna (LISA). Based on its sensitivity, we consider…

General Relativity and Quantum Cosmology · Physics 2024-10-01 Chantal Pitte , Quentin Baghi , Marc Besançon , Antoine Petiteau

Perturbed Kerr black holes emit gravitational radiation, which (for the practical purposes of gravitational-wave astronomy) consists of a superposition of damped sinusoids termed quasi-normal modes. The frequencies and time-constants of the…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Ioannis Kamaretsos , Mark Hannam , Sascha Husa , B. S. Sathyaprakash

According to the no-hair theorem, astrophysical black holes are uniquely described by the Kerr metric. In order to test this theorem with observations in either the electromagnetic or gravitational-wave spectra, several Kerr-like spacetimes…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Tim Johannsen

We show that second-generation gravitational-wave detectors at their design sensitivity will allow us to directly probe the ringdown phase of binary black hole coalescences. This opens the possibility to test the so-called black hole…