Robert Lipshitz's 2017-2018 Tour

Dates and venues

Sept. 14
Syracuse, NY
(Syracuse Geometry & Topology Seminar)
The Alexander polynomial and knot Floer homology: properties, applications, and questions
Sept. 15
Buffalo, NY
(U. Buffalo Topology Day)
Bordered Heegaard Floer homology and incompressible surfaces
Oct. 4
Los Angeles, CA
(USC Colloquium)
Trivial tangles and Floer homology
Nov. 19
Austin, TX
(Texas Geometry and Topology Conference)
Bordered Floer homology and compressible surfaces
Jan. 5
Los Angeles, CA
(UCLA Topology Workshop)
Bordered HF^- with torus boundary: formal structure
Jan. 22
Stanford, CA
(Stanford Symplectic Geometry Seminar)
Bordered involutive Heegaard Floer homology
May 4
Bozeman Montana
(Montana State Topology Seminar)
Khovanov homology and homotopy
May 11
Montréal, Canada
(Perspectives on bordered Heegaard Floer theory school)
Bordered-sutured Floer homology and boundary-parallel tangles
June 20, 21, or 22
Princeton, NJ
(Princeton RTG Mini-Conference)
Computing involutive HF-hat
July 20, 21, or 22
Los Angeles, CA
(Categorification and Quantum 3-Manifold Invariants Workshop)
Spectral platform algebras and modules
Aug. 7
Rio de Jeneiro, Brazil
(International Congress of Mathematicians)
Stable homotopy refinements and Khovanov homology

Abstracts

September 14, Syracuse Geometry & Topology Seminar.
The Alexander polynomial and knot Floer homology: properties, applications, and questions
Abstract. After recalling the definition of the Alexander polynomial, we will describe a refinement, knot Floer homology, introduced by Ozsváth-Szabó and Rasmussen. We will then discuss some properties of the Alexander polynomial which have been lifted to knot Floer homology, some properties that have not been lifted, and some properties of knot Floer homology that seem not to be visible from the Alexander polynomial. Some applications will be interspersed throughout. Most of this is due to other people, but part is joint work with Ozsváth-Thurston, Treumann, or Hendricks-Sarkar.

September 15, University of Buffalo Toplogy Day.
Bordered Heegaard Floer homology and incompressible surfaces
Abstract. Heegaard Floer homology is an invariant of closed 3-manifolds and 4-manifolds with boundary; bordered Heegaard Floer homology is an extension of one variant of Heegaard Floer homology to 3-manifolds with boundary. After sketching some of the formal structure of these theories and some of their basic definitions, we will deduce from a theorem of Ni’s that bordered Heegaard Floer homology detects homologically essential compressing disks. Time permitting, we will also give a version of this statement for tangles, and talk about what a computer implementation of this algorithm looks like. This is joint work with Akram Alishahi, and builds on earlier joint work with Peter Ozsváth and Dylan Thurston.

October 4, University of Southern California Departmental Colloquium.
Trivial tangles and Floer homology
Abstract. Tangles are pieces of knots. After introducing tangles, two notions of equivalence for them, and some examples and (knot-theoretic) uses of them, we will sketch an invariant which can be used to check if tangles are boundary parallel---one notion of triviality for tangles. This is joint work with A. Alishahi, building on earlier work with P. Ozsváth and D. Thurston.

November 19, Texas Topology Conference at UT Austin.
Bordered Floer homology and compressible surfaces
Abstract. After recalling some of the key properties of bordered Heegaard Floer homology, we will describe how it detects homologically essential compressing disks, and how bordered-sutured Floer homology detects boundary-parallel tangles. Time permitting, we will also sketch an algorithm to compute bordered-sutured Floer homology. This is joint work with Akram Alishahi, and uses earlier joint work with Peter Ozsváth and Dylan Thurston.

January 5, UCLA Topology Workshop.
Bordered HF^- with torus boundary: formal structure
Abstract. We will outline the formal structure of bordered HF^- with torus boundary and illustrate it with a few computations. This is joint work in progress with Peter Ozsváth and Dylan Thurston.

January 22, Stanford Topology Seminar.
Bordered involutive Heegaard Floer homology
Abstract. Involutive Heegaard Floer homology is a partial analogue of Pin(2)-equivariant Seiberg-Witten Floer homology, defined by Hendricks-Manolescu. We will start by reviewing their construction, asserting some applications, and mentioning what is needed for a full analogue. We will then discuss how to compute the “hat” version of involutive Heegaard Floer homology using bordered Floer homology; this is joint work with Kristen Hendricks, and uses earlier joint work with Peter Ozsváth and Dylan Thurston.

May 4, Montana State Topology Seminar.
Khovanov homology and homotopy
Abstract. Khovanov homology is a refinement of the Jones polynomial of a knot, and the Khovanov spectrum is a further refinement of that. We will start by recalling a definition of the Jones polynomial of a knot, then sketch the definitions of Khovanov homology and its stable homotopy refinement. We will conclude by mentioning a few applications and open questions. The new part is joint work with Tyler Lawson and Sucharit Sarkar, and there is related work by Hu-Kriz-Kriz.

May 11, Perspectives on Bordered Floer Homology, an ISM Discovery School.
Bordered-sutured Floer homology and boundary-parallel tangles
Abstract. We will sketch the construction of bordered-sutured Floer homology, focusing on the case of tangles. We will then discuss how bordered-sutured Floer homology makes (the ``hat'' variant of) knot Floer homology and, more generally, sutured Floer homology algorithmically computable and how this can be used to detect boundary-parallel tangles. This is joint work with Alishahi, building on earlier work of Zarev and joint work with Ozsváth-Thurston.

June 20, Low-dimensional topology and its interactions with symplectic geometry.
Computing involutive HF-hat
Abstract. Hendricks-Manolescu's "involutive Heegaard Floer homology" is a variant of Heegaard Floer homology which capitalizes on the conjugation action on spin^c structures. In this talk we will discuss an algorithm for computing the simplest version of involutive Heegaard Floer homology, involutive HF-hat. This is joint work with Kristen Hendricks, and builds on earlier joint work with Peter Ozsváth and Dylan Thurston.

July 20, Categorification and Quantum 3-Manifold Invariants Workshop .
Spectral platform algebras and modules
Abstract. We will sketch stable homotopy refinements of Chen-Khovanov / Stroppel’s platform algebras and bimodules. This is joint work with Tyler Lawson and Sucharit Sarkar.


Previous years: 2015-2016, 2016-2017.