报告题目: Consistency constraints on EFTs coupled to gravity

报 告 人: Anna Tokareva (Hangzhou Institute for Advanced Study)

报告时间: 2025年11月13日15:30

报告地点：物理楼W260

内容摘要：Effective field theories are subject to a set of requirements following from fundamental principles of quantum field theory, such as unitarity, causality, locality. These properties can be implemented with the use of dispersion relations for the scattering amplitudes. The main difficulty for obtaining EFT constraints in the presence of gravity is related to the graviton pole, which makes the required dispersion relations divergent in the forward limit. I will formulate a method which allows to overcome this issue and obtain a lower bound on the self-coupling of the scalar field, in the presence of gravity. Such a constraint can be straightforwardly generalised to the gauge field interaction. It can be seen as a reflection of the Weak Gravity Conjecture originally formulated by N. Arkani-Hamed as a statement that gravity must be the weakest force, compared to the other interactions in low-energy effective field theory (EFT). I will also review the further constraints on Einstein-Maxwell EFT following from black hole physics and show their unexpected coincidence with causality requirements for quasinormal modes of near extremal charged black holes.

报告人简介：Anna Tokareva is an Associate Researcher at Hangzhou Institute for Advanced Study since June 2023. She got her PhD in 2016 from the Institute for Nuclear Research RAS in Moscow, Russia after doctoral studies at the Moscow State University. After that she got postdoctoral experience at EPFL, Lausanne, Switzerland, Institute for Nuclear Research, Moscow, Russia, University of Jyvaskyla, Finland, and Imperial College London in the UK. Her main scientific results and interests are at the borderline between cosmology, quantum gravity and formal aspects of quantum field theory.