The Effective Action and Geometry of Closed N=2 Strings

Abstract

N=2 closed strings have been recently divided in hep-th/0211147 to two T-dual families denoted by αand β. In (2,2) signature both families have one scalar in the spectrum. The scalar in the β-string is known to be a deformation of the target space Kähler potential and the dynamics is that of self-dual gravity. In this paper we compute the effective action of the scalar in the α-string. The scalar is a deformation of a potential that determines the metric, torsion and dilaton. The scalar is free and the dynamics is that of a self-dual curvature with torsion.

1+12pages, latex2e, v2: a reference and footnote added, v3: a section added with an example of a gravitational background of the α-string, references added