Two lectures on TwoDimensional Gravity
Abstract
(from the talk:) I shall here speak on gravity in (1+1)dimensional spacetime  lineal gravity. The purpose of studying lower dimensional theories, and specifically lower dimensional gravity, is to gain insight into difficult conceptional issues, which are present and even more opaque in the physical (3+1)dimensional world. Perhaps lessons learned in the lowerdimensional setting can be used to explicate physical problems. Moreover, if we are lucky, the lowerdimensional theories can have a direct physical relevance to modelling phenomena that is actually dynamically confined to the lower dimensionality. This is what happened with (2+1)dimensional gravity: gravitational physics in the presence of cosmic strings (infinitely long, perpendicular to a plane) is adequately described planar gravity. Indeed the recently discussed causality puzzles raised by ``Gott time machines'' were resolved with the help of the lowerdimensional model...
 Publication:

arXiv eprints
 Pub Date:
 November 1995
 arXiv:
 arXiv:grqc/9511048
 Bibcode:
 1995gr.qc....11048J
 Keywords:

 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 23 pages in REVTeX. Talk presented at LASSF II, Caracas, Venezuela, October 1995