Physics Colloquium: Vortices, Black Holes and Hair

Event Details

  • Speaker(s): Ruth Gregory
  • Date:
  • Time: 3:30 PM
  • Location: MacN 101

Abstract

Black holes are one of the most fascinating objects in theoretical gravity- they are the logical conclusion of a description in which the nonlinear attraction of matter eventually causes it to cut off from the outside world. The description of a black hole is particularly simple - they are characterised by mass, charge and angular momentum - the lack of larger numbers of parameters being known as "no hair" theorems. Yet the no hair theorems ignore the effects of nonlinearity in physical systems, and in particular, nonlinearity in the field theories used to describe matter. I will discuss how black holes can acquire very spectacular hair when symmetries of nature are spontaneously broken - in the form of vortices or even domain walls. I will show how these vacuum defects interact with the event horizon, and cause it to buckle and change in shape. Although the black hole can be bland, it can have rather literal, and very long hair!