LAUSR

Dáfni F. Z. Marchioro, Daniel L. Nedel Universidade Federal da Integração Latino-Americana Avenida Tancredo Neves 6731, Foz do Iguaçu, Brasil Abstract In this letter, the open string is quantized in a time dependent black hole background. The geometry is defined through an adiabatic approximation of the Vaydia metric. The worldsheet two-point function is derived and it is shown to have the same type of singularity as the flat space one. However, the equal times two-point function depends on the particular Cauchy surface where the worldsheet fields are defined. Finite temperature effects are incorporated through the Liouville-von Neumann approach to non equilibrium thermodynamics.