Nikolay Bobev (KU Leuven): CFTs on Squashed Spheres and the Thermal Effective Action

Thermal Seminars 29/09/26 ➤ Nikolay Bobev (KU Leuven): CFTs on Squashed Spheres and the Thermal Effective Action I will discuss 3d CFTs placed on a deformed three-sphere in two complementary limits. For small deformations, the free energy of the theory can be computed using conformal perturbation theory techniques, which I will discuss in some detail. For large squashing deformations of the Hopf fiber of the three-sphere, the free energy is governed by a 2d thermal effective action, which also captures the free energy of the CFT on other Seifert manifolds. I will present explicit results for the Wilson coefficient of this effective action for free fields, the critical O(N) model, and holographic CFTs. Based on arXiv:2606.30716 [hep-th] ➤ The Thermal Seminars are a series of webinars on finite temperature quantum field theories, conformal field theories, and related topics, from holography, to black holes and bootstrap approaches. ■ Website: sites.google.com/view/thermalseminars ■ Email: thermaldynamicsseminars@gmail.com ✎Organized by: Julien Barrat (Princeton U.), Deniz Bozkurt (KU Leuven), Enrico Marchetto (DESY), Alessio Miscioscia (YITP)