讲座主题：A Stacky Perspective of Topological Sectors in Scalar Model

专家姓名：张柏阳

工作单位：河南大学

讲座时间：2024年09月30日10:00-11:30

讲座地点：化馆北322

主办单位：hy590海洋之神平台物理与电子信息学院

内容摘要：

Topological solitons, kinks in our case, define their own superselection sectors, and Hilbert states therein don't mix with that in trivial vacuum in time evolution. Renormalization is crucial in obtaining finite order-by-order contributions in formal perturbation theory. However, the matching of renormalization schemes between different topological sectors was for a long time not well defined hence lead to ambiguity. In this tal we answer the question: If a vacuum sector Hamiltonian is regularized by an energy cutoff, how is the one-kink sector Hamiltonian regularized? We find that it is not regularized by an energy cutoff, indeed normal modes of all energies are present in the kink Hamiltonian, but rather the decomposition of the field into normal mode operators yields coefficients which lie on a constrained surface that forces them to become small for energies above the cutoff. This explains the old observation that an energy cutoff of the kink Hamiltonian leads to an incorrect one-loop kink mass.

主讲人介绍：

张柏阳博士，河南大学数学与统计学院博士后，本科毕业于兰州大学物理学院，研究生毕业于中国科学院近代物理研究所。曾在匈牙利科学院，魏格纳理论物理中心（2018-2019）及明尼苏达大学（2019-2022）从事博士后研究，在JHEP, Phys.Rev.D，Phys. Lett. B 等杂志发表文章十余篇。主要从事高能物理与数学物理方面的研究，包括：1）量子场论中拓扑结构；2）场论量子化的一般数学结构，特别是代数量子场论在标量场中的应用；3）Resurgence理论在物理模型中的应用，尤其是与瞬子有效相互作用的联系。