- You are here:
- GT Home
- Home
- News & Events

Series: Geometry Topology Seminar

Series: Geometry Topology Seminar

Series: Geometry Topology Seminar

Series: Geometry Topology Seminar

Series: Geometry Topology Seminar

Series: Geometry Topology Seminar

Series: Geometry Topology Seminar

We will discuss a relation between some notions in three-dimensional topology and four-dimensional aspects of knot theory.

Series: Geometry Topology Seminar

Alexandru Oancea:
Title: Symplectic homology for cobordisms
Abstract: Symplectic homology for a Liouville cobordism - possibly filled
at the negative end - generalizes simultaneously the symplectic homology of
Liouville domains and the Rabinowitz-Floer homology of their boundaries. I
will explain its definition, some of its properties, and give a sample
application which shows how it can be used in order to obstruct cobordisms
between contact manifolds. Based on joint work with Kai Cieliebak and Peter
Albers.
Basak Gürel:
Title: From Lusternik-Schnirelmann theory to Conley conjecture
Abstract: In this talk I will discuss a recent result showing that whenever
a closed symplectic manifold admits a Hamiltonian diffeomorphism with
finitely many simple periodic orbits, the manifold has a spherical homology
class of degree two with positive symplectic area and positive integral of
the first Chern class. This theorem encompasses all known cases of the
Conley conjecture (symplectic CY and negative monotone manifolds) and also
some new ones (e.g., weakly exact symplectic manifolds with non-vanishing
first Chern class). The proof hinges on a general Lusternik–Schnirelmann
type result that, under some natural additional conditions, the sequence of
mean spectral invariants for the iterations of a Hamiltonian diffeomorphism
never stabilizes. Based on joint work with Viktor Ginzburg.

Series: Geometry Topology Seminar

Let S be a Riemann surface of type (p,1), p > 1. Let f be a point-pushing pseudo-Anosov map of S. Let t(f) denote the translation length of f on the curve complex for S. According to Masur-Minsky, t(f) has a uniform positive lower bound c_p that only depends on the genus p.Let F be the subgroup of the mapping class group of S consisting of point-pushing mapping classes. Denote by L(F) the infimum of t(f) for f in F pseudo-Anosov. We know that L(F) is it least c_p. In this talk we improve this result by establishing the inequalities .8 <= L(F) <= 1 for every genus p > 1.

Series: Geometry Topology Seminar

This is joint work with Hyam Rubinstein. Matveev and Piergallini independently show that the set of triangulations of a three-manifold is connected under 2-3 and 3-2 Pachner moves, excepting triangulations with only one tetrahedron. We give a more direct proof of their result which (in work in progress) allows us to extend the result to triangulations of four-manifolds.