Conformal Tightness of Holographic Scaling in Black Hole Thermodynamics

The near-horizon conformal symmetry of nonextremal black holes is shown to be a mandatory ingredient for the holographic scaling of the scalar-field contribution to the black hole entropy. This conformal tightness is revealed by semiclassical first-principle scaling arguments through an analysis of the multiplicative factors in the entropy due to the radial and angular degrees of freedom associated with a scalar field. Specifically, the conformal SO(2,1) invariance of the radial degree of freedom conspires with the area proportionality of the angular momentum sums to yield a robust holographic outcome.Comment: 23 pages, 1 figure. v2 & v3: expanded explanations and proofs, references added, typos corrected; v3: published versio

Method and apparatus for electromagnetic powder deposition

The present invention provides a method for depositing powder particles on a substrate. The method comprises forming a planar plasma armature, accelerating the plasma armature, accelerating a column of gas with the plasma armature; and accelerating the powder particles with the column of gas. The present invention provides for a railgun, comprising first and second conducting rails, and first and second insulating rails. The insulating and conducting rails form a bore of the railgun. The first and second conducting rails are separated by the insulating rails. At least one of the rails has a port in the wall thereof, the port is adapted to introducing powder particles into the bore.Board of Regents, University of Texas Syste

Black Hole Complementarity vs. Locality

The evaporation of a large mass black hole can be described throughout most of its lifetime by a low-energy effective theory defined on a suitably chosen set of smooth spacelike hypersurfaces. The conventional argument for information loss rests on the assumption that the effective theory is a local quantum field theory. We present evidence that this assumption fails in the context of string theory. The commutator of operators in light-front string theory, corresponding to certain low-energy observers on opposite sides of the event horizon, remains large even when these observers are spacelike separated by a macroscopic distance. This suggests that degrees of freedom inside a black hole should not be viewed as independent from those outside the event horizon. These nonlocal effects are only significant under extreme kinematic circumstances, such as in the high-redshift geometry of a black hole. Commutators of space-like separated operators corresponding to ordinary low-energy observers in Minkowski space are strongly suppressed in string theory.Comment: 32 pages, harvmac, 3 figure

The Stretched Horizon and Black Hole Complementarity

Three postulates asserting the validity of conventional quantum theory, semi-classical general relativity and the statistical basis for thermodynamics are introduced as a foundation for the study of black hole evolution. We explain how these postulates may be implemented in a ``stretched horizon'' or membrane description of the black hole, appropriate to a distant observer. The technical analysis is illustrated in the simplified context of 1+1 dimensional dilaton gravity. Our postulates imply that the dissipative properties of the stretched horizon arise from a course graining of microphysical degrees of freedom that the horizon must possess. A principle of black hole complementarity is advocated. The overall viewpoint is similar to that pioneered by 't~Hooft but the detailed implementation is different.Comment: (some misprints in equations have been fixed), 48 pages (including figures), SU-ITP-93-1

Quantum Cosmology of Generalized Two--Dimensional Dilaton Gravity Models

The quantum cosmology of two-dimensional dilaton-gravity models is investigated. A class of models is mapped onto the constrained oscillator-ghost-oscillator model. A number of exact and approximate solutions to the corresponding Wheeler-DeWitt equation are presented. A wider class of minisuperspace models that can be solved in this fashion is identified. Supersymmetric extensions to the induced gravity theory and the bosonic string theory are then considered and closed-form solutions to the associated quantum constraints are derived. The possibility of applying the third-quantization procedure to two-dimensional dilaton-gravity is briefly discussed.Comment: 28 pages, late

Notes on magnetic coil design

This brief report summarizes work done which addressed the issue of sizing the USTX Ohmic heating solenoid by imposing some physical constraints on the TF and OH coil designs. A computer code is used for this study. The TF coil sets the solenoid inner radius at 0.10 meters. Allowing a 2.5 cm gap between the inner plasma radius and outer radius of the solenoid fixes the latter at 0.185 meters. The OH solenoid radial thickness is then 0.085 meters. The plasma current obtainable is I{sub p} = 1.05 megamp