Geometry and dynamics of a tidally deformed black hole

Squeezars: Tidally Powered Stars Orbiting a Massive Black Hole

We propose that there exists a class of transient sources, “squeezars”, which are stars caught in highly eccentric orbits around a massive (m . 10M⊙) black hole (MBH), whose atypically high luminosity (up to a significant fraction of their Eddington luminosity) is powered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic cente...

Geometry of Black Hole Thermodynamics

The Hessian of the entropy function can be thought of as a metric tensor on the state space. In the context of thermodynamical fluctuation theory Ruppeiner has argued that the Riemannian geometry of this metric gives insight into the underlying statistical mechanical system; the claim is supported by numerous examples. We study this geometry for some families of black holes. It is flat for the ...

String Propagation in a Black Hole Geometry

We consider string theory in the background of the two-dimensional black hole as described by the SL(2, R)/U(1) coset theory recently introduced by Witten. We study the spectrum of this conformal field theory, and give explicit representations for the tachyon vertex operators in terms of SL(2, R) matrix elements. This is used to compute the scattering of strings off the black hole and to show t...

Deformed Density Matrix and Quantum Entropy of the Black Hole

In the present work the approach-density matrix deformation-earlier developed by the author to study a quantum theory of the Early Universe (Planck's scales) is applied to study a quantum theory of black holes. On this basis the author investigates the information paradox problem, entropy of the black hole remainders after evaporation, and consistency with the holographic principle. The possibi...

Quantum Geometry and Black Hole EntropyA