CHRIS HALCROW

Research

The focus of my research during my PhD has been on Skyrmions. These are topological solitons - solutions of a nonlinear (ie tricky) field theory which are stable and exist thanks to the topology of the system. To find a nice analogy: take off your belt and flip over one side. A knot will form and, if you clamp each side of the belt, it won't go away. You can move the knot around and even assign it a position and velocity if you'd like. Now replace the belt with all of space and the knot is a Skyrmion. This topological origin of the Skyrmion makes it an interesting mathematical object. But there's also a physical interest.

Witten showed that, in a certain limit, these knot-like Skyrmions should model nuclei: things like protons, neutons, alpha-particles and Uranium-238. The B-Skyrmion models a nucleus with B protons and neutrons. To make contact with experimental data you have to quantise the Skyrmions. This is tricky and the simplest method (called the zero mode approximation) leads to some problems. My PhD focuses on quantisation beyond the zero mode approximation.

Below are details on some individual projects. Click on an image to find out more!


Any questions? Get in touch at cjh95@cam.ac.uk.