Thermal Polyakov bootstrap

Abstract

We derive thermal Polyakov bootstrap equations for CFT two-point functions on $S^1_\beta\times\mathbb R^{d-1}$. Combining the thermal OPE with a dispersion relation and the method of images gives a representation in blocks that satisfy Kubo-Martin-Schwinger (KMS) covariance. Their local expansions contain additional thermal blocks at classical double-twist dimensions. Matching the prescribed physical OPE requires cancellation of these generated contributions, yielding explicit linear equations for thermal OPE coefficients, including any compensating terms required by the reconstruction. We formulate the equations for bosonic scalar correlators and antiperiodic scalar structures extracted from fermion correlators, and find consistent solutions in analytically tractable thermal CFTs. The coefficient matrix, which we call the Polyakov matrix, connects the large-spin expansion to KMS consistency and reduces to minus the identity on the classical double-twist spectrum. This structure suggests a numerical approach to the three-dimensional Ising CFT that combines known low-lying vacuum data with a self-consistent large-spin tail.