We consider a general Einstein-scalar-Gauss-Bonnet theory with a coupling function f(ϕ). We demonstrate that black-hole solutions appear as a generic feature of this theory since a regular horizon and an asymptotically flat solution may be easily constructed under mild assumptions for f(ϕ). We show that the existing no-hair theorems are easily evaded, and a large number of regular black-hole solutions with scalar hair are then presented for a plethora of coupling functions f(ϕ).
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.120.131102 | DOI Listing |
PeerJ Comput Sci
November 2024
Department of Electrical Engineering, Future University in Egypt, New Cairo, Egypt.
In recent years, the Internet of Things has played a dominant role in various real-time problems and given solutions via sensor signals. Monitoring the patient health status of Internet of Medical Things (IoMT) facilitates communication between wearable sensor devices and patients through a wireless network. Heart illness is one of the reasons for the increasing death rate in the world.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
Maryland Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742, USA.
We numerically construct stationary, rotating black binaries in general relativity with a positive cosmological constant. We consider identical black holes with either aligned or anti-aligned spins. Both cases have less entropy than the corresponding single Kerr-Schwarzschild-de Sitter black hole with the same total angular momentum and cosmological horizon entropy.
View Article and Find Full Text PDFPhys Rev Lett
October 2024
Institut Denis Poisson, UMR-CNRS 7013, Université de Tours, Parc de Grandmont, 37200 Tours, France.
We construct static and axially symmetric magnetically charged hairy black holes in the gravity-coupled Weinberg-Salam theory. Large black holes merge with the Reissner-Nordström (RN) family, while the small ones are extremal and support a hair in the form of a ring-shaped electroweak condensate carrying superconducting W currents and up to 22% of the total magnetic charge. The extremal solutions are asymptotically RN with a mass below the total charge, M<|Q|, due to the negative Zeeman energy of the condensate interacting with the black hole magnetic field.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Physics, K. N. Toosi University of Technology, P. O. Box 15875-4416, Tehran, Iran.
Mimetic gravity has gained significant appeal in cosmological contexts, but static spherically symmetric space-times within the baseline theory are highly non-trivial: the two natural solutions are a naked singularity and a black hole space-time obtained through an appropriate gluing procedure. We study the shadow properties of these two objects, finding both to be pathological. In particular, the naked singularity does not cast a shadow, whereas the black hole casts a shadow which is too small.
View Article and Find Full Text PDFPhys Rev Lett
September 2024
Institut de Physique Théorique, Université Paris-Saclay, CEA, CNRS, F-91191 Gif-sur-Yvette Cedex, France.
We apply a formulation of Einstein's general relativity with only cubic interactions for deriving the metric of a Schwarzschild black hole to all orders in perturbation theory. This cubic interactions formulation coupled to effective worldline action of a massive point particle allows to derive a recursion relation for the form factors of the off-shell graviton emission current. The unique solution to the recursion relation leads to the Schwarzschild black-hole solution in four dimensions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!