204004757
WZW model based on the extended de Sitter group
We study the WZW model based on the centrally extended 2D de Sitter algebra. We obtain the spacetime metric and its explicitly conformally flat expression. The symmetries of the spacetime are found by identifying the Killing vectors with the group generators. The energy-momentum tensor obtained from the affine-Sugawara construction agrees with that from the more conventional approach. The exact center charge agrees to one-loop order with the one-loop beta function equations. We have also studied the representations of the corresponding enveloping Virasoro algebra.
16200472
Radiation from a moving scalar source.
We study classical radiation and the quantum bremsstrahlung effect of a moving point scalar source. Our classical analysis provides another example of resolving a well-known apparent paradox, that of whether or not a constantly accelerating source radiates. Quantum mechanically, we show that for a scalar source with arbitrary motion the tree level emission rate of scalar particles in the inertial frame equals the sum of emission and absorption rates of zero-energy Rindler particles in the Rindler frame. We then explicitly verify this result for a source undergoing constant proper acceleration.
11133030
Time-dependent open string solutions in (2+1)-dimensional gravity.
We find general, time-dependent solutions produced by open string sources carrying no momentum flow in 2+1 dimensional gravity. The local Poincar\'e group elements associated with these solutions and the coordinate transformations that transform these solutions into Minkowski metric are obtained. We also find the relation between these solutions and the planar wall solutions in 3+1 dimensions.
120336908
Explicit solutions for the running coupling constant and the separatrix of quantum field theories
Starting with 't Hooft's definition of a renormalized coupling constant, we give an explicit solution for the running coupling constant. We also give an exact expression for the ''separatrix'' of a quantum field theory, i.e., the line that separates the asymptotically free region of the g-plane from the nonasymptotically free one. Our results hold for all four dimensional renormalizable theories such as QCD, QED, and phi/sup 4//sub 4/. The implication of the results is discussed. copyright 1989 Academic Press, Inc.