We find multiple relations between extremal black holes in string theory and 2-and 3-qubit systems in quantum information theory. We show that the entropy of the axion-dilaton extremal black hole is related to the concurrence of a 2-qubit state, whereas the entropy of the STU black holes, BPS as well as non-BPS, is related to the 3-tangle of a 3-qubit state. We relate the 3-qubit states with th...

We explore the physical consequences of a recently discovered class of exact solutions to five dimensional Kaluza-Klein theory. We find a number of surprising features including: (1) In the presence of a Kaluza-Klein bubble, there are arbitrarily large black holes with topology S. (2) In the presence of a black hole or a black string, there are expanding bubbles (with de Sitter geometry) which ...

We investigate whether or not the Hawking-Page phase transition is possible to occur in three dimensions. Starting with the simplest class of LanczosLovelock action, thermodynamic behavior of all AdS-type black holes without charge falls into two classes: Schwarzschild-AdS black holes in even dimensions and Chern-Simons black holes in odd dimensions. The former class can provide the Hawking-Pag...

Cool thermal emission components have recently been revealed in the X-ray spectra of a small number of ultraluminous X-ray sources (ULXs) with ergs s 1 in nearby galaxies. These components can be well 40 L ≥ 10 X fitted with accretion disk models, with temperatures approximately 5–10 times lower than disk temperatures measured in stellar-mass Galactic black holes when observed in their brightes...

Over the past three decades, black holes have played an important role in quantum gravity, mathematical physics, numerical relativity and gravitational wave phenomenology. However, conceptual settings and mathematical models used to discuss them have varied considerably from one area to another. Over the last five years a new, quasi-local framework was introduced to analyze diverse facets of bl...

Based on the fact that the near horizon geometry of the extremal Schwarzschild-de Sitter black holes is Nariai geometry, we define the black holes of Nariai class as the configuration whose near-horizon geometry is factorized as two dimensional de Sitter space-time and some compact topology, that is Nariai geometry. We extend the entropy function formalism to the case of the black holes of Nari...

Massive black holes appear to be present in the nuclei of almost all galaxies, but their genesis and evolution are not well understood. As astrophysical black holes are completely characterized by their masses and spins, the observed joint distribution of these quantities contains important clues to their history. We examine the coevolution of mass and spin in binary merger growth scenarios. We...

Charged rotating black holes of Einstein-Maxwell-Chern-Simons theory in odd dimensions, D ≥ 5, may possess a negative horizon mass, while their total mass is positive. This surprising feature is related to the existence of counterrotating solutions, where the horizon angular velocity Ω and the angular momentum J possess opposite signs. Black holes may further possess vanishing horizon angular v...

We extend our recent discussion of four-dimensional black holes bound to a two-brane to include a negative cosmological constant on the brane. We find that for large masses, the solutions are precisely BTZ black holes on the brane, and BTZ ‘black strings’ in the bulk. For smaller masses, there are localized black holes which look like BTZ with corrections that fall off exponentially. We compute...

B holes are among the strangest predictions of Einstein’s general theory of relativity: regions of spacetime in which gravity is so strong that nothing—not even light—can escape. More precisely, a black hole is a singularity in spacetime surrounded by an event horizon, a surface that acts as a perfect one-way membrane: matter and radiation can enter the event horizon, but, once inside, can neve...