Knotted surfaces in 4manifolds
October 2628, 2018, University of Massachusetts, Amherst, MA
Organizing Committee
R. Inanc Baykur (UMass Amherst), Weimin Chen (UMass Amherst) and Daniel Ruberman (Brandeis University)
Invited speakers


Goals
The aim of this 3day conference is to bring together active researchers in knotted surfaces in 4manifolds, ranging from leading experts to recent PhDs and graduate students, and provide a panorama of the field through a variety of talks and discussion sessions. The talks will start at 2:30 Friday afternoon and finish by 1pm Sunday to accommodate participant travel.
Registration and support
[Funding applications are now closed.]
Funding is available for conference participation. Support requests should be made at the registration link by September 14, 2018. We particularly encourage graduate students and recent PhDs to apply. For full consideration, junior participants should also have a reference letter
emailed to [baykur at math dot umass dot edu] by the funding request deadline.
We have reserved rooms for all the invited speakers and participants coming from outside of Western Massachusetts at the UMass Hotel and Conference Center. Please provide your planned
dates of stay and accommodation preferences at the registration link above. With very few exceptions, all the rooms are reserved for the nights of Friday, October 26 and Saturday, October 27, so please plan your travel accordingly. Further inquiries regarding accommodation should be made to [wchen at math dot umass dot edu].
This event is sponsored by the National Science Foundation Grant DMS1522633.
Travel
The closest airport to Amherst is the Bradley (Hartford/Springfield) Airport, and there are shuttle services from/to UMass Amherst. The second major airport in the area is the Logan (Boston) Airport (1,52hrs distance), which however requires an additional bus commute between Boston and Amherst. Greyhound buses serve between Amherst and many other locations such as Boston and New York.
Schedule
Friday, October 26 2:00  2:30pm Registration 2:30  3:30pm LambertCole 3:30  4:00pm REFRESHMENTS 4:00  5:00pm Sunukjian 5:15  6:45pm Discussion 
Saturday, October 27 9:30  10:30am Gabai 10:30  10:45am TEA 10:45  11:45am Schwartz 12:00  1:00pm Yasui 2:30  3:30pm Suciu 3:30  4:00pm REFRESHMENTS 4:00  5:00pm Starkston 5:15  6:45pm Discussion 
Sunday, October 28 9:30  10:30am Hedden 10:30  10:45am TEA 10:45  11:45am Zemke 12:00  1:00pm Miller 
All talks and the discussion sessions will be held at Lederle Graduate Research Tower, Room 1634. Tea and refreshments will be served in the lounge area next to LGRT 1634.
Titles and abstracts

David Gabai
The general 4dimensional light bulb theorem
We discuss the theorem that in a compact 4manifold that has no 2torsion, homotopy implies smooth isotopy for smooth embedded 2spheres with a common embedded transverse sphere. By transverse sphere we mean a sphere with trivial normal bundle that intersects each of the other spheres transversely exactly once. 
Matthew Hedden
Satellites of infinite rank in the smooth concordance group
I'll discuss the way satellite operations act on the concordance group, and raise some questions and conjectures. In particular, I'll conjecture that satellite operations are either constant or have infinite rank, and reduce this to the difficult case of winding number zero satellites. I'll then talk about how to use SO(3) gauge theory to provide a general criterion sufficient for the image of a satellite operation to generate an infinite rank subgroup of smooth concordance, and use this to address the winding zero case. This is joint work with Juanita PinzonCaicedo. 
Peter LambertCole
Bridge trisections and the Thom conjecture
The classical degreegenus formula computes the genus of a nonsingular algebraic curve in the complex projective plane. The wellknown Thom conjecture posits that this is a lower bound on the genus of smoothly embedded, oriented and connected surface in CP^2. The conjecture was first proved twentyfive years ago by Kronheimer and Mrowka, using SeibergWitten invariants. In this talk, we will describe a new proof of the conjecture that combines contact geometry with the novel theory of bridge trisections of knotted surfaces. Notably, the proof completely avoids any gauge theory or pseudoholomorphic curve techniques. 
Maggie Miller
Trisections of surface complements and surgery on RP^2s
A relative trisection is a decomposition of a 4manifold with boundary which induces an open book on the boundary. Two relative trisections can only be glued if they induce the same open book (with opposite orientation). I will show how to relatively trisect the complement of a surface S in a 4manifold X. When S is an RP^2 of Euler number +2 or 2, we can control the resulting open book so that we may perform surgery (a "Price twist") on X along S. In particular, when X=S^4, this yields a trisected homotopy 4sphere. This work is joint with Seungwon Kim. 
Hannah Schwartz
Using 2torsion to obstruct topological isotopy
It is well known that two knots in S^3 are ambiently isotopic if and only if there is an orientation preserving automorphism of S^3 carrying one knot to the other. In this talk, we will examine a family of smooth 4manifolds in which the analogue of this fact does not hold, i.e. each manifold contains a pair of smoothly embedded, homotopic 2spheres that are related by a diffeomorphism, but not smoothly isotopic. In particular, the presence of 2torsion in the fundamental groups of these 4manifolds can be used to obstruct even a topological isotopy between the 2spheres; this shows that Gabai's recent ``4D Lightbulb Theorem" does not hold without the 2torsion hypothesis. 
Laura Starkston
Symplectic isotopy problems
We will discuss some problems and results about symplectic surfaces in 4manifolds, particularly in the complex projective plane. The main question is to classify symplectic surfaces up to symplectic isotopy. If the surface has singularities, we restrict the isotopies to the class of surfaces with the same model singularities. 
Alex Suciu
On the topology of complex line arrangements
I will discuss some recent advances in our understanding of the multiple connections between the combinatorics of an arrangement of complex hyperplanes, the topology of its complement and boundary manifold, and the monodromy of its Milnor fibration. 
Nathan Sunukjian
Smoothly knotted, topologically trivial tori
Surfaces in a 4manifold can be topologically isotopic, but not smoothly isotopic. In this talk, we will discuss a method for constructing such "exotic" embeddings of tori. The novel feature of this construction is that our tori are topologically trivial (in the sense that they bound a topologically embedded solid torus in the 4manifold), but smoothly nontrivial. These examples can be constructed in any elliptic surface (among other 4manifold), and are examples of surfaces that are not ribbon, but are stabily ribbon. This is joint work with Neil Hoffman. 
Kouichi Yasui
Minimal genus functions and smooth structures of 4manifolds
We discuss applications of minimal genus functions of 4manifolds to their smooth structures. We first briefly review methods for distinguishing smooth structures of 4manifolds by the functions. We then focus on a question whether all exotic smooth structures of a compact 4manifold can be generated by twisting a fixed compact submanifold, and we give a partial negative answer by introducing an invariant of smooth structures determined by minimal genus functions. 
Ian Zemke
The stabilization distance and link Floer homology
Given a knot K in S^3, we consider the set of oriented surfaces in B^4 which bound K. A natural question is how many stabilizations and destabilizations one must perform to move from one surface to another. In this talk, we consider a metric on the set of surfaces bounding K, which is based on how many times one must stabilize or destabilize to move from one surface to another. We will describe how the link Floer TQFT can be used to construct lower bounds.