报告题目：旋度力及其外延（Curl forces and beyond）
报 告 人：Dr. Sir Michael Victor Berry （英国布里斯托尔大学）
报告时间：2016年6月15日（周三）14:00
报告地点：校本部E301
邀 请 人：陈玺 教授
主办单位：永利物理系
报告简介：
Forces depending on position but which are not derivable from a potential, that is, forces with non-zero curl, give rise to dynamics that is not Hamiltonian or Lagrangian, while also being non-dissipative. Noether’s theorem does not apply, so the link between symmetries and conservation law’s is broken. The physical existence of curl forces has been controversial and the subject of controversy among engineers. But an example is familiar in optics: force on a dielectric particle in an optical field. Motion under curl forces near optical vortices can be understood in detail, and numemrics reveals a new kind of chaos. The full series of ‘superadiabatic’ correction forces is derived, leading to an exact slow manifold in which fast (internal) and slow (external) motion of the particle is separated.
