Geometric Topology

Working group seminar @HU

 General information

Time & place: Biweekly Mondays at 11:00 in Seminar room 1.315 Rudower Chaussee 25, 12489 Berlin

Format: 60min informal talk (followed by 30min discussion)

Participation:     Everyone interested in geometric topology is welcome to participate.

Organizers:       Marc Kegel and Chun-Sheng Hsueh

 Schedule WiSe 24/25

Nov 4th Chun-Sheng Hsueh

  Braidedness of open books

We will discuss the following article.

 

Nov 11th Marc Kegel

  Kirby calculus of contact 3-manifolds

 

Nov 25th Marc Kegel

  Kirby calculus of contact 3-manifolds II

 

Dec 16th David Suchodoll

  The bridge index

  Classification of 2-bridge knots

Jan 20th Farid A. Azar León

  Khovanov homology

Jan 28th Valentina Bais (SISSA, Trieste)

  Exotic non-orientable 4-manifolds

Feb 3rd Frank Selensky

  Chern classes of open books

 

Feb 10th Kuldeep Saha (TCG-CREST Kolkata, online)

  Surfaces in 4-manifolds and extendible mapping classes

Abstract: Given a proper embedding of an orientable surface in a 4-manifold, we study which surface diffeomorphisms can be induced by a diffeomorphism of the ambient 4-manifold. As an application, we answer a question on the existence of universal open books on a 5d manifold. We call a 5d open book universal if every 3d open book with connected binding admits an open book embedding in it.