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"Reparametrization path integral and effective action of superstring in AdS5 x S5"

Relatore: Prof. Yuri Makeenko- ITEP - Moscow

Sala Feynman
26 Marzo 2013 ore 16.30

Reparametrization path integral plays the crucial role for constructing stringy representations of the Wilson loop in QCD, describing the minimal surface at the saddle point and its quantum fluctuations in the semiclassical approximation. I consider the reparametrization path integral in anti-de Sitter space (AdS) by extending Douglas' algorithm for finding minimal surfaces to AdS. The case of a circular boundary contour is elaborated. I discuss applications to N=4 super Yang--Mills: a circular Wilson loop and the Schwinger effect, where a semiclassical correction to the critical constant electric field is computed. The results are compared with the one-loop effective action of the Green-Schwarz superstring in AdS5XS5, which is reconsidered by properly accounting for the ghost and longitudinal determinants.