Department of Mathematical Sciences

309 SCEN

University of Arkansas

Fayetteville, AR 72701

P 479-575-3351

F 479-575-8630

E-mail: math@uark.edu

# Past Redbud Conferences

### Redbud Fall 2017 Topology Conference

April 27-29, 2017

Reynolds Center on Campus

University of Arkansas at Fayetteville

The Redbud Topology conference is a regional conference in topology and related areas, with participants from the University of Arkansas, the University of Oklahoma, Oklahoma State University, and elsewhere. The conference will run all day Friday and all morning on Saturday, ending by 1 PM. There will also be a session on Thursday afternoon as a warm-up for graduate students. There will be dinner outing on Friday evening.

**Speakers:**

Hannah Alpert, (Brown University)

Khalid Bou-Rabee, (The City College of New York)

Moon Duchin, (Tufts University)

Mark Feighn, (Rutgers University-Newark)

Vincent Guirardel, (Université de Rennes 1)

Ilya Kapovich, (University of Illinois at Urbana-Champaign)

Priyam Patel, (University of California at Santa Barbara)

Kasra Rafi, (University of Toronto)

Andrew Sale, (Vanderbilt University)

Sam Taylor, (Yale University)

**Schedule:** The full schedule and talk abstracts are

**Register:** We encourage participants to register so that we will have a head-count for the event.
We expect to have some funds available to reimburse participant expenses. Priority
will be given to registrations received prior to March 27.

**Inclusiveness:** The Redbud Topology Conference is supported by the University of Arkansas, the University
of Oklahoma, Oklahoma State University and the National Science Foundation. As scholars
representing these institutions, we pay special attention to their firm commitments
to equal opportunity and diversity. In order to uphold these ideals, we strive to
make each Redbud Conference an inclusive event and will not tolerate discrimination
based on race, color, religion, national origin, sex (including gender identity, sexual
orientation, and pregnancy), age, disability, genetic information or parental status.
As part of this mission, the organizers are happy to provide details of local childcare
options and lactation rooms for nursing mothers upon request.

Further information on the commitment to inclusiveness held by each institution can be found here:

The National Science Foundation's post award requirements

The University of Arkansas's equal opportunity statement

The University of Oklahoma's equal opportunity statement

Oklahoma State University's equal opportunity statement

**Sponsors:** Participant support is generously provided by the NSF award DMS-1702102 and in part by the Department of Mathematical Sciences at the University of Arkansas.

**Organizers:** Matt Clay*, Matt Day*, Max Forester, Neil Hoffman, Yo'av Rieck*, Henry Segerman,
Jing Tao.

(*local organizers)

Questions or comments? Please contact Matt Clay.

### Redbud 2014 Fall Conference

November 1, 2014

University of Arkansas

SCEN 408

This is a regional conference in topology, broadly interpreted.

9:00 a.m. to 4:45 p.m.

Speakers

Thomas Church, Stanford University

Matt Day, University of Arkansas

Matthew Durham, University of Michigan

Robert Tang, University of Oklahoma

Pengcheng Xu, Oklahoma State University

Participant support provided by NSF award DMS-1419391.

Questions or comments? Please contact Matt Clay.

Organizers: Matt Clay, Matt Day, Yo'av Reick, Jeremy Van Horn-Morris

The Redbud Topology conference is a regional conference in topology and related areas, with participants from the University of Arkansas, the University of Oklahoma, Oklahoma State University, and elsewhere.

2014 Spring - April 11-13, 2014, University of Oklahoma

2013 Fall - October 26, 2013, Oklahoma State University

### Redbud Conference

March 8, 2013

**Schedule of Events**

**Graduate Workshop - Friday, March 8**

SCEN 322

John Etnyre and Gordana Matic

workshop - 8:30 a.m. to noon (with breaks)

lunch - noon to 1:30 p.m.

workshop - 1:30 p.m. to 5 p.m. (with breaks)

**Saturday, March 9**

SCEN 408

**Matt Hedden **- 9 a.m. to 10 a.m.

(30 minute break)

**Elena Pavalescu **- 10:30 a.m. to 11:30 a.m.

**Lunch** - 11:30 a.m. to 1:30 p.m.

**John Etnyre **- 1:30 p.m. to 2:30 p.m.

(30 minute break)

**Josh Sabloff **- 3 p.m. to 4 p.m.

(30 minute break)

**Lisa Traynor** - 4:30 p.m. to 5:30 p.m.

**Sunday, March 10**

**Dan Rutherford** - 9:30 a.m. to 10:30 a.m.

(30 minute break)

**Shea Vela-Vick** - 11 a.m. to noon

Optional afternoon trip to Crystal Bridges Museum of American Art, Bentonville

**Speakers**

**John Etnyre **(Georgia Tech)

Title: Contact structures on 5 manifolds

*Abstract: Contact structures, especially in dimension 3, have been studied extensively
for quite some time but we still do not know which odd dimensional manifolds support
such structures. In this talk I will discuss the proof that all almost contact 5 manifolds
do admit contact structures. *

**Matt Hedden** (Michigan State)

Title: Some recent progress on topologically slice knots

*Abstract: Modulo a 4-dimensional equivalence relation, the set of knots in the 3-sphere
can be endowed with a group structure. The resulting group is called the concordance group and, perhaps
surprisingly, the group depends on whether we work with homeomorphisms or diffeomorphisms.
Particularly important to understanding this distinction is the set of topologically
slice knots: those knots which bound topologically flat embedded disks in the 4-ball.
I'll give an introduction and overview of the subgroup of concordance generated by
topologically slice knots, and discuss recent work which provides the first examples
of (two-) torsion elements in this subgroup. The new results which I'll mention are
joint work with Se-Goo Kim and Charles Livingston.*

**Elena Pavelescu** (Oklahoma State)

Title: Invariants of Legendrian graphs

*Abstract: A Legendrian graph is a graph embedded in such a way that its edges are
everywhere tangent to the contact structure. We first extend the classical invariants
Thurston-Bennequin number and rotation number to Legendrian graphs as the ordered
set of tb's and rot's taken over the set of cycles of the graph. We show that graph
G can be Legendrian realized with all cycles unknots of maximal tb=-1 if and only
if G doesn't contain K_4 as a minor. We find all pairs (tb, rot) that can be realized
as the invariants of a Legendrian theta-graph and we investigate how good is a pair
(tb, rot) at distinguishing the Legendrian type of a graph. This is joint work with
Danielle O'Donnol. *

**Dan Ruthorford **(University of Arkansas)

Title and abstract: TBA

**Joshua Sabloff** (Haverford College)

Title: Geography of Legendrian Submanifolds

*Abstract: I will discuss the structure of the space of Legendrian submanifolds in
the standard contact R^{2n+1}, especially for n at least 2. The first lens I will
use is geography, i.e. a survey of which sets of invariants can be realized by Legendrian
submanifolds Using a construction involving embedded Legendrian surgery. I will examine
the geography question for the non-classical generating family homology invariant
and will show that optimal results can be achieved (this is joint work with Lisa Traynor
and Frederic Bourgeois). The second lens is that of homotopy, and I will extend the
examples used in the analysis of the geography question to construct loops of Legendrian
spheres that are non-contractible in the space of Legendrians but are contractible
in the smooth category (this is joint work with Mike Sullivan). *

**Lisa Traynor **(Bryn Mawr College)

Title: The Geography of Lagrangian Cobordisms

*Abstract: In topology, cobordisms define a fundamental equivalence relation on the
set of compact manifolds: two compact, n-dimensional manifolds are cobordant if their
disjoint union is the boundary of a (n+1)-dimensional manifold. I will discuss cobordisms
that satisfy extra geometrical conditions imposed by symplectic and contact structures.
Namely, I will discuss Lagrangian cobordisms between Legendrian manifolds. In contrast
to the smooth setting, this cobordism relation no longer defines an equivalence relation
on the set of Legendrian submanifolds. There are numerous interesting “geography”
questions about the existence of Lagrangian cobordisms. I will discuss some obstructions
to and constructions of Lagrangian cobordisms that give some geographic information.*

**Shea Vela-Vick** (LSU)

Title: Transverse knots, infinite cyclic covers and Heegaard Floer homology.

*Abstract: In recent years, Heegaard Floer theory has proven an invaluable tool for
studying contact manifolds and the Legendrian and transverse knots they contain. I
plan to discuss a method for defining a variant of Heegaard Floer theory for infinite
cyclic covers of transverse knots in the standard contact 3-sphere. This invariant
takes the form of a Z[t,t^-1]-module and generalizes one defined in joint work with
Baldwin and Vertesi for transverse knots braided about open book decompositions. In
this talk, I will discuss how our invariant is constructed and present some basic
properties. This is joint work with Tye Lidman and Sucharit Sarkar.*

### Graduate Workshop

Friday, March 8

**John Etnyre **(Georgia Institute of Technology) and **Gordana Matic **(University of Georgia).

1. Etnyre- Contact and almost contact manifolds Abstract: Contact geometry is a venerable
subject that arose in various concrete situations such as celestial mechanics and
thermodynamics. In the last few decades they have been much studied and been shown
to have surprising connections to many areas of mathematics. In this talk I will introduce
contact structures on manifolds and discuss "obvious" properties a manifold must have
to admit a contact structure.

2. Matic- Contact topology, convex surfaces and open books.

3. Etnyre- Legendrian knot theory.

4. Matic- Contact topology and Heegaard Floer Homology

All are welcome to attend. If you'd like to participate, plan on arriving on Thursday and let us know either by

November 3rd, 2012, University of Oklahoma, Nielsen Hall room 251.

This is a regional conference in topology, broadly interpreted. The target audience is mathematicians from the University of Arkansas, Oklahoma State University, and the University of Oklahoma.

The conference will run from 9:30 am to 4:15 pm, with coffee beforehand and dinner afterwards.

Speakers:

Matt Day, University of Arkansas

Funda Gultepe, University of Oklahoma

Dale Rolfsen, University of British Columbia

Jeremy Van Horn-Morris, University of Arkansas

We encourage participants to register so that we will have a head-count for the event. Please register by Thursday October 18 if at all possible. We have some funds available to reimburse participant expenses. To be considered for support, please register.

Location, hotel and travel information can be found here.

A map showing various items of interest can be found here.

Questions or comments? Please contact Max Forester (forester@math.ou.edu).

*Updated October 30th, 2012.*

2012 Spring - March 3-4, 2012, Oklahoma State University

November 19th, 2011, University of Arkansas, SCEN building room 408.

This is a regional conference in topology, broadly interpreted. The target audience is mathematicians from the University of Arkansas, Oklahoma State University, and the University of Oklahoma.

The conference will run from 9:30 am-4:15 pm. There will be dinner afterwards.

Speakers:

Matt Clay, Allegheny University

Jesse Johnson, Oklahoma State

Joel Louwsma, University of Oklahoma

Dan Rutherford, University of Arkansas

We encourage participants to register so that we will have a head-count for the event. We expect to have some funds available to reimburse participant expenses (NSF support is pending). To be considered for support, please register.

Location, hotel and travel information can be found here.

Questions or comments? Please contact Matt Day (matthewd@uark.edu).

*Updated November 12th, 2011.*

2006 Spring - first Arkansas-Oklahoma Workshop in Geometry and Topology, University of Arkansas