Ghost Tachyon Condensation, Branelike States and Extra Time Dimension
Abstract
NSR superstring theory contains a tower of physical vertex operators (branelike states) which exist at nonzero pictures only, i.e. are essentially mixed with superconformal ghosts. Some of these states are massless, they are responsible for creating Dbranes. Other states are tachyonic (called ghost tachyons) creating a problem for the vacuum stability of the NSR model. In this paper we explore the role played by these tachyonic states in string dynamics. We show that the ghost tachyons condense on Dbranes, created by massless branelike states. Thus the vacuum stability is achieved dynamically, as the effective ghost tachyon potential exactly cancels the Dbrane tension, in full analogy with Sen's mechanism. As a result, from perturbative NSR model point of view, massless and tachyonic branelike states appear to live in a parallel world, as the brane is screened by the tachyonic veil. We extend the analysis to the braneantibrane pair in AdS space and show that in this case due to the effect of the ghost tachyon condensation one can construct extra timedimensional phenomenological models without tachyons and antibranes.
 Publication:

arXiv eprints
 Pub Date:
 May 2001
 arXiv:
 arXiv:hepth/0105055
 Bibcode:
 2001hep.th....5055C
 Keywords:

 High Energy Physics  Theory
 EPrint:
 24 pages, harvmac.tex