Duality in superstring compactifications with magnetic field backgrounds
Abstract
Motivated by the work of Polchinski and Strominger on type IIA theory, where the effect of nontrivial field strenghts for pform potentials on a CalabiYau space was discussed, we study fourdimensional heterotic string theory in the presence of a magnetic field on a 2cycle in the internal manifold, for both N = 4 and N = 2 cases. We show that at special points in the moduli space certain perturbative charged states become tachyonic and stabilize the vacuum by acquiring vacuum expectation values, thereby restoring supersymmetry. We discuss both the cases where the tachyons appear with a tower of Landau levels, which become light in the limit of large volume of the 2cycle, and the case where such Landau levels are not present. In the latter case it is sufficient to restrict the analysis to the quartic potential for the tachyon. On the other hand, in the former case it is necessary to include the Landau levels in the analysis of the potential; for toroidal and orbifold examples, we give an explicit CFT description of the new supersymmetric vacuum. The resulting new vacuum turns out to be in the same class as the original supersymmetric one. Finally, using duality, we discuss the role of the Landau levels on the type IIA side.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1998
 DOI:
 10.1016/S05503213(97)006536
 arXiv:
 arXiv:hepth/9708075
 Bibcode:
 1998NuPhB.511..611A
 Keywords:

 High Energy Physics  Theory
 EPrint:
 26 pages, LaTeX, 1 figure