Exact TT deformation of two-dimensional Maxwell theory

Authors: Luca Griguolo, Rodolfo Panerai, Jacopo Papalini, Domenico Seminara

Preprint: UUITP-15/22

TT-deformed two-dimensional quantum Maxwell theory on the torus is examined, taking into account nonperturbative effects in the deformation parameter μ. We study the deformed partition function solving the relevant flow equation at the level of individual flux sectors. Summing exactly the “instanton” series, we obtain a well-defined expression for the partition function at arbitrary μ. For μ > 0, the quantum spectrum of the theory experiences a truncation, the partition function reducing to a sum over a finite set of positive-energy states. For μ < 0 instead, the appearance of nonperturbative contributions in μ drastically modifies the structure of the partition function, regularizing its naive divergences through instanton-like subtractions. For each flux sector, we show that the semiclassical contribution is dominated by the deformed classical action. The theory is observed to undergo infinite-order phase transitions for certain values of μ, associated with the vanishing of Polyakov-loop correlators.