In this paper we consider the metric entropies of the maps of an iterated function system deduced from a black hole which are known the Bekenstein-Hawking entropies and its subleading corrections. More precisely, we consider the recent model of a Bohr-like black hole that has been recently analysed in some papers in the literature, obtaining the intriguing result that the metric entropies of a black hole are created by the metric entropies of the functions, created by the black hole principal quantum numbers, i.e., by the black hole quantum levels. We present a new type of topological entropy for general iterated function systems based on a new kind of the inverse of covers. Then the notion of metric entropy for an Iterated Function System ( I F S ) is considered, and we prove that these definitions for topological entropy of are equivalent. It is shown that this kind of topological entropy keeps some properties which are hold by the classic definition of topological entropy for a continuous map. We also consider as another type of topological entropy for an I F S which is based on the topological entropies of its elements and it is also an invariant object under topological conjugacy. The relation between Axiom and the average entropy is investigated.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7512249 | PMC |
http://dx.doi.org/10.3390/e20010056 | DOI Listing |
Phys Rev Lett
December 2024
Universidade Federal de Pernambuco, Departamento de Física, 50670-901, Recife, Brazil.
We employ the isomonodromic method to study linear scalar massive perturbations of Kerr black holes for generic scalar masses Mμ and generic black hole spins a/M. We find that the longest-living quasinormal mode and the first overtone coincide for (Mμ)_{c}≃0.370 4981 and (a/M)_{c}≃0.
View Article and Find Full Text PDFLiving Rev Relativ
January 2025
Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX UK.
In the recent years, primordial black holes (PBHs) have emerged as one of the most interesting and hotly debated topics in cosmology. Among other possibilities, PBHs could explain both some of the signals from binary black hole mergers observed in gravitational-wave detectors and an important component of the dark matter in the Universe. Significant progress has been achieved both on the theory side and from the point of view of observations, including new models and more accurate calculations of PBH formation, evolution, clustering, merger rates, as well as new astrophysical and cosmological probes.
View Article and Find Full Text PDFStud Hist Philos Sci
January 2025
Philosophy Department, Tufts University, United States of America; Black Hole Initiative, Harvard University, United States of America; Lichtenberg Group for History and Philosophy of Physics, University of Bonn, Germany. Electronic address:
In this paper, I provide an account of direct (vs. indirect) detection in gravitational-wave astrophysics. In doing so, I highlight the epistemic considerations that lurk behind existing debates over the application of the term "direct".
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Hainan Engineering Research Center of Tropical Ocean Advanced Optoelectronic Functional Materials, Hainan International Joint Research Center of Marine Advanced Photoelectric Functional Materials, Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, Key Laboratory of Functional Materials and Photoelectrochemistry of Haikou, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China.
The CsPbBr perovskite exhibits strong environmental stability under light, humidity, temperature, and oxygen conditions. However, in all-inorganic perovskite solar cells (PSCs), interface defects between the carbon electrode and CsPbBr limit the carrier separation and transfer rates. We used black phosphorus (BP) nanosheets as the hole transport layer (HTL) to construct an all-inorganic carbon-based CsPbBr perovskite (FTO/c-TiO/m-TiO/CsPbBr/BP/C) solar cell.
View Article and Find Full Text PDFOpen Res Eur
January 2025
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, 91125, USA.
The study of transient and variable events, including novae, active galactic nuclei, and black hole binaries, has historically been a fruitful path for elucidating the evolutionary mechanisms of our universe. The study of such events in the millimeter and submillimeter is, however, still in its infancy. Submillimeter observations probe a variety of materials, such as optically thick dust, which are hard to study in other wavelengths.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!