Non-extremal fractional branes

Abstract

We construct non-extremal fractional D-brane solutions of type-II string theory at the Z_2 orbifold point of K3. These solutions generalize known extremal fractional-brane solutions and provide further insights into N=2 supersymmetric gauge theories and dual descriptions thereof. In particular, we find that for these solutions the horizon radius cannot exceed the non-extremal enhancon radius. As a consequence, we conclude that a system of non-extremal fractional branes cannot develop into a black brane. This conclusion is in agreement with known dual descriptions of the system.Comment: 29 pages, LaTeX. v2: 30 pages; equation (3.4) corrected; typos fixed; discussion in section 3 streamlined and slightly extended; reference adde