Tying a knot in a piece of string can be a hard practical problem.
It seems even harder to tie a field into a knot — say a function from real 3-dimensional space to the complex numbers such that the function is zero on a curve which is a given knot or link. Nevertheless, several ways of doing this have been proposed in recent years, linking several areas in modern optics such as optical vortices, position-dependent polarization, optical helicity and tightly-focused beams. I will discuss recent progress in this area, including creating laser beams containing a variety of different knots and links, detecting knottedness in random speckle fields and relations with knots in other systems such as fluids, nuclear physics and quantum chaos. I will conclude with some comparisons with 3D topological textures and skyrmions.
Biography: His research is primarily in the physics of waves (optical, electromagnetic, quantum, …), and how geometry and topology may be used to understand and control their propagation and scattering.
Particular interests include singular optics and structured light (optical vortices, optical angular momentum, polarization singularities), and applied topology in physics (especially applications of knot theory in optics, quantum mechanics and molecular biology).
He has published over 100 research papers, proceedings, reviews, and book chapters, working with various other theorists and experimentalists around the world.