题 目：Shape modes of ℂP1 vortices
主讲人：Nora Gavrea
单 位：英国利兹大学
时 间：11月4日18:00
ZOOM: 713 668 5659
密 码: 123456
摘 要：In this talk, I will introduce the gauged sigma model with target ℂP1 defined on a Riemannian surface Σ, concentrating on the case Σ=ℝ2. This model admits topological solitons called vortices which attain a topological lower energy bound characterized by a pair of degrees (k+,k-). They come in two different species, which may coexist. I will present a geometric formalism to compute the second variation of the energy functional around a general (k+,k-)-vortex. On a non-compact domain, such as ℝ2, it is a nontrivial question whether the associated Jacobi operator has any L2 normalisable eigensections. Such eigensections are called "shape modes" in the physics literature, and, if present, they have a strong effect on the low energy scattering behaviour of vortices. I will prove (on ℝ2) that all vortices have at least one shape mode, and that such shape modes can be constructed by solving a simple scalar Schroedinger-type eigenvalue problem. The formalism rests on deep structural properties of the model (its so called Bogomolny decomposition), and it can be adapted to a wide class of structurally similar field theories. This is based on joint work with Derek Harland and Martin Speight.
简 介：Nora Gavrea is a PhD student of Prof. Martin Speight at Leeds University, UK.
