Dbrane decay in twodimensional string theory
Abstract
We consider unstable D0branes of two dimensional string theory, described by the boundary state of Zamolodchikov and Zamolodchikov [36] multiplied by the Neumann boundary state for the time coordinate t. In the dual description in terms of the c = 1 matrix model, this D0brane is described by a matrix eigenvalue on top of the upside down harmonic oscillator potential. As suggested by McGreevy and Verlinde [25], an eigenvalue rolling down the potential describes Dbrane decay. As the eigenvalue moves down the potential to the asymptotic region it can be described as a free relativistic fermion. Bosonizing this fermion we get a description of the state in terms of a coherent state of the tachyon field in the asymptotic region, up to a nonlocal linear field redefinition by an energydependent phase. This coherent state agrees with the exponential of the closed string onepoint function on a disk with Sen's marginal boundary interaction for t which describes D0brane decay.
 Publication:

Journal of High Energy Physics
 Pub Date:
 July 2003
 DOI:
 10.1088/11266708/2003/07/045
 arXiv:
 arXiv:hepth/0305159
 Bibcode:
 2003JHEP...07..045K
 Keywords:

 Bosonic Strings Dbranes Tachyon Condensation;
 High Energy Physics  Theory
 EPrint:
 19 pages, harvmac, minor changes