ON STRING THEORY AND AXIONIC STRINGS AND INSTANTONS
Soo-Jong Rey · University of North Texas Digital Library (University of North Texas) · 1991
Progress in understanding exact superconformal field theories of four-- dimensional axionic instantons and axionic strings is reported. Superstring theory is the first promising candidate of quantum gravity, per-haps unified with strong and electroweak interactions. Still, our current under-standing is largely based on weak coupling perturbative analysis. On the other hand, most of interesting physics of superstring seem to require nonperturba-tive understandings: just to name. a few, dynamical supersymmetry breaking, cosmological constant problem and spacetime singularity are such examples. Therefore, in this talk, I will discuss what I find one of the most ‘interesting topics in superstring theory to the above direction: stringy solitons and instan-tons. Recently, considerable progress in nonperturbative aspects of noncritical strings has been made. Here, I will restrict myself to critical superstrings in ten-dimensions, suitably compactified to four dimensions keeping N = 1 spacetime supersymmetry. At scales well below that of compactification, massless string excitations may be described by a low-energy supergravity theory. It is observed that, in all known string theories, there arises ubiquitously a massless gravity supermul-tiplet: graviton, dilaton and Kalb-Ramond (axion) fields. The other massless excitations depends largely on the way a specific compactification scheme is