|April-2017||Paul Sutcliffe||Paul Sutcliffe gave the opening talk on "Knots and Vortices" at the Workshop on Solitons: Integrability, Duality and Applications, held at the International Centre for Theoretical Physics in Sao Paulo, Brazil|
|April-2017||Jon Steed||Invited talk, "Gel-Based Approaches to Novel Solid Forms" at the 23rd International Conference on the Chemistry of the Organic Solid State, Stellenbosch, South Africa|
|April-2017||Lauren Scanlon||Invited talk, "The cultural evolution of knot tying: an analysis of the cultural transmission of granny and reef knots" at European Human Behaviour and Evolution Association (EHBEA) 2017, Paris, France|
|March-2017||Dave Foster and Alexander Taylor||Bristol group visit to Durham to provide an update on current work|
|March-2017||Dr Hayder Salman, University of East Anglia||Threading Knotted and Tangled Filamentary Phase Defects in Complex Scalar Fields Experimental advances that have been made in recent years have made it increasingly possible to create matter wave fields in atomic Bose-Einstein condensates containing knotted or linked filamentary phase defects. These defects correspond to topological excitations in the form of quantized superfluid vortices. Knotted vortices have already been created and studied under controlled conditions in classical fluids. However, in these cases, vorticity acts to erode the vortical core of the vortices. An advantage of quantized superfluid vortices is that the vorticity remains concentrated along filaments throughout the dynamics. Nevertheless, quantum effects allow reconnections to occur that can change the topology of the fluid. This makes matter wave (as well as optical) fields an ideal setting in which to quantify helicity for topologically non-trivial vortex configurations. Although an excellent microscopic model exists to study the dynamics of such defects in superfluids, several challenges exist in generating an initial wavefunction containing knotted configurations. In this talk, I will show, using methods from differential geometry, how one can imprint any desired vortex configuration into the wavefunction. Using the imprinted fields, we perform numerical simulations of several knotted defects to illustrate their dynamical behaviour. I will also discuss the role of helicity for superfluid vortices.|
|Session Chair, "Knotting in Filaments and Fields", APS March Meeting, New Orleans, USA. Talks involving SPOCK members within the session were:|
Keith Alexander, Alexander Taylor, Mark Dennis, "Virtual knotting in proteins and other open curves"
Mervyn Miles, David Foster, Annela Seddon, David Phillips, David Carberry, Miles Padgett, Mark Dennis, "Tying Knots in DNA with Holographic Optical Tweezers"
Mark Dennis, "Optical Vortex Knots in Tightly-focused Light Beams"
Ben Bode, Mark Dennis, "A Knotted Complax Scalar Field for any Knot"
Alexander Taylor, Mark Dennis, "Stability of Knotted Vortices in Wave Chaos"