Non-perturbative Supersymmetry Breaking and Finite Temperature Instabilities in N=4 Superstrings

摘要

We obtain the non-perturbative effective potential for the dualfive-dimensional N=4 strings in the context of finite-temperature regarded as abreaking of supersymmetry into four space-time dimensions. Using the propertiesof gauged N=4 supergravity we derive the universal thermal effective potentialdescribing all possible high-temperature instabilities of the known N=4superstrings. These strings undergo a high-temperature transition to a newphase in which five-branes condense. This phase is described in detail, usingboth the effective supergravity and non-critical string theory in sixdimensions. In the new phase, supersymmetry is perturbatively restored butbroken at the non-perturbative level.