A Time-Like Naked Singularity (2004)
Goswami, Rituparno, Joshi, Pankaj S., Vaz, Cenalo, Witten, Louis
We construct a class of spherically symmetric collapse models in which a naked singularity may develop as the end state of collapse. The matter distribution considered has negative radial and...
Canonical Quantization of Collapsing Dust (2004)
Witten, Louis; Department Of Physics, University Of Cincinnati; Bmworkshop@mate.polimi.it
Exact Quantum State of Collapse and Black Hole Radiation (2003)
Vaz, Cenalo, Witten, Louis, Singh, T. P.
We construct an exact quantum gravitational state describing the collapse of an inhomogeneous spherical dust cloud using a lattice regularization of the Wheeler-DeWitt equation. In the semiclassical...
Quantum general relativity and Hawking radiation (2002)
Vaz, Cenalo, Kiefer, Claus, Singh, T. P., Witten, Louis
In a previous paper we have set up the Wheeler-DeWitt equation which describes the quantum general relativistic collapse of a spherical dust cloud. In the present paper we specialize this equation to...
Toward a Quantization of Null Dust Collapse (2001)
Vaz, Cenalo, Witten, Louis, Singh, T. P.
Spherically symmetric, null dust clouds, like their time-like counterparts, may collapse classically into black holes or naked singularities depending on their initial conditions. We consider the...
Quantum Black Holes from Quantum Collapse (2001)
The Schwarzschild black hole can be viewed as the special case of the marginally bound Lema\^\i tre-Tolman-Bondi models of dust collapse which corresponds to a constant mass function. We have...
Type IIB orientifolds with discrete torsion (2001)
Karp, Robert L, Esposito, F. Paul, Witten, Louis
We consider compact four-dimensional ${\bf Z_N}\times {\bf Z_M}$ type IIB orientifolds, for certain values of $N$ and $M$. We allow the additional feature of discrete torsion and discuss the...
Toward a Midisuperspace Quantization of LeMaitre-Tolman-Bondi Collapse Models (2000)
Vaz, Cenalo, Witten, Louis, Singh, T. P.
LeMa\^\i tre-Tolman-Bondi models of spherical dust collapse have been used and continue to be used extensively to study various stellar collapse scenarios. It is by now well-known that these models...
The Quantum States and the Statistical Entropy of the Charged Black Hole (2000)
We quantize the Reissner-Nordstr\"om black hole using an adaptation of Kucha\v{r}'s canonical decomposition of the Kruskal extension of the Schwarzschild black hole. The Wheeler-DeWitt equation turns...
Spherical gravitational collapse: tangential pressure and related equations of state (1999)
Barve, Sukratu, Singh, T. P., Witten, Louis
We derive an equation for the acceleration of a fluid element in the spherical gravitational collapse of a bounded compact object made up of an imperfect fluid. We show that non-singular as well as...
A simple derivation of the naked singularity in spherical dust collapse (1999)
Barve, Sukratu, Singh, T. P., Vaz, Cenalo, Witten, Louis
We describe a simple method of determining whether the singularity that forms in the spherically symmetric collapse of inhomogeneous dust is naked or covered. This derivation considerably simplifies...
Mass Quantization of the Schwarzschild Black Hole (1998)
We examine the Wheeler-DeWitt equaton for a static, eternal Schwarzschild black hole in Kucha\v r-Brown variables and obtain its energy eigenstates. Consistent solutions vanish in the exterior of the...
Detecting Event Horizons and Stationary Surfaces (1998)
Gass, Richard G., Esposito, F. Paul, Wijewardhana, L. C. R., Witten, Louis
We have investigated the behavior of three curvature invariants for Schwarzschild, Reissner-Nordstr{\o}m, Kerr, and Kerr-Newman black holes. We have also studied these invariants for a...
The Quantum Stress-Tensor in Self-Similar Spherical Dust Collapse (1998)
Barve, Sukratu, Singh, T. P., Vaz, Cenalo, Witten, Louis
We calculate the quantum stress tensor for a massless scalar field in the 2-d self-similar spherical dust collapse model which admits a naked singularity. We find that the outgoing radiation flux...
On the Spectrum of the Radiation from a Naked Singularitry (1998)
In the final stages of collapse, quantum radiation due to particle creation from a naked singularity is expected to be significantly different from black hole radiation. In certain models of collapse...
Particle Creation in the Marginally Bound, Self Similar Collapse of Inhomogeneous Dust (1998)
Barve, S., Singh, T. P., Vaz, Cenalo, Witten, Louis
We consider the evaporation of the (shell focusing) naked singularity formed during the self-similar collapse of a marginally bound inhomogeneous dust cloud, in the geometric optics approximation. We...
Cosmic censorship and spherical gravitational collapse with tangential pressure (1997)
We study the spherical gravitational collapse of a compact object under the approximation that the radial pressure is identically zero, and the tangential pressure is related to the density by a...
Quantum Naked Singularities in 2d Dilaton Gravity (1996)
Roughly speaking, naked singularities are singularities that may be seen by timelike observers. The Cosmic Censorship conjecture forbids their existence by stating that a reasonable system of energy...
Do Naked Singularities Form? (1995)
A naked singularity is formed by the collapse of a Sine-Gordon soliton in 1+1 dimensional dilaton gravity with a negative cosmological constant. We examine the quantum stress tensor resulting from...
Soliton Induced Singularities in 2 d Gravity and their Evaporation (1994)
Positive energy singularities induced by Sine-Gordon solitons in 1+1 dimensional dilaton gravity with positive and negative cosmological constant are considered. When the cosmological constant is...
Wilson Loops and Black Holes in 2+1 Dimensions (1994)
In 2+1 dimensional Chern-Simons gravity, Wilson loops in the three dimensional Anti de Sitter group, $SO(2,2)$, reproduce the spinning black hole of Ba\~nados, Teitelboim and Zanelli (BTZ) by...
Formation and Evaporation of a Naked Singularity in 2D Gravity (1993)
We describe a classical configuration of conformal matter forming a naked singularity and discuss its subsequent Hawking evaporation within the context of two dimensional dilaton gravity. The one...
We argue that the collapse of a non-rotating object into a black hole has not been proved to be dynamically stable. There are unstable modes and one should explore whether they may be excited. This...
Asymptotic structure of space-time / edited by F. Paul Esposito and Louis Witten (1977)
Esposito, F. Paul, Witten, Louis
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