"New asymptotic invariants for mesure preserving vector fields."Rydzek, MarianneGiven a non-singular vector field $X$ preserving a measure $\mu$ on $\mathbb{S}^3$, can we construct invariants up to $\mu$-preserving diffeomorphisms ? In this talk I will present the most famous invariant of this kind, helicity, and explain its connection with the linking number of knots. Then I will introduce two new asymptotic invariants which also arise from knot theory : the trunkenness defined by Dehornoy-Rechtman and the bridge number of vector fields. |
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