Title: Helicity and linking for 3-dimensional Anosov flows
Speaker: Richard Sharp – University of Warwick, UK
Abstract: Given a volume-preserving flow on a closed 3-manifold, one can, under certain conditions, define an invariant called the helicity. This was introduced as a topological invariant in fluid dynamics by Moffatt and measures the total amount of linking of orbits. When the manifold is a real homology 3-sphere, Arnold and Vogel identified this with the so-called asymptotic Hopf invariant, obtained by taking the limit of the normalised linking number of two typical long orbits. We obtain a similar result for null-homologous volume preserving Anosov flows, in terms of weighted averages of periodic orbits. (This is joint work with Solly Coles.)
Zoom link: https://osu.zoom.us/j/94136097274
Meeting ID: 941 3609 7274
Password: Mixing
Recorded Talk: https://osu.zoom.us/rec/share/cYO8hmX37fCGqR5DfrnHAnCNK04udNHsLvehiztiGOKAOEiByu-F2FpNPl7GDCGZ.WyVU6UdNkxaxw0fQ