Speaker
Description
Using hydrodynamics, r.k.a. thermal effective field theory, I will show that locality and Weyl invariance constrain the coefficients of various angular-velocity structures appearing in the high-temperature expansion of the thermal partition function (Z) of even-dimensional CFTs. This leads to an infinite hierarchy of relations among these coefficients. Remarkably, the first of these relations determines the (a)-type Weyl anomaly.
I will then reinterpret these relations in the large-spin regime. For local operators in CFT with large spin (J), allowing the twist to be large but parametrically smaller than J, the leading entropy is fixed up to a theory-dependent function of a universal scaling variable involving twist and spin—a phenomenon we identified and termed “Semi-universality” in arXiv:2512.00158 (in contrast to the “super-universality” we found in 2D CFT in arXiv:2505.02897 with van Rees and Qiao). The new results reflect the fact that the subleading semi-universal functions are themselves constrained by differential relations. If time permits, I will conclude with a sketch of the derivation of stronger-than-unitarity spectral bounds from this setup and extension of semi-universality to the averaged OPE data at large spin and twist. Based on arXiv:2512.00158 with Anand, Benjamin, Kumar, Minwalla, Mukherjee, Rahaman; and ongoing work with Advant, Anand, Benjamin, Kumar, Minwalla, Mukherjee, Rahaman, Ray.