The SGGTC seminar meets on Fridays in Math 407 from 2:00 pm to 3:00 pm, unless noted otherwise (in red). If you would like to be on the mailing list, please subscribe here. 

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Schedule


Date
Speaker
Title
Sep 19, 2pm
Viktória Földvári (Columbia/Rényi Institute)
 Legendrian Two-Bridge Knots
Sep 26, 2pm
Randy Van Why (Georgia Tech)
 Non-affine Stein manifolds and normal crossing divisors
Oct 3, 2pm
Sriram Raghunath (Rutgers University)
  
Oct 10, 2pm Johan Asplund (Stony Brook)  
Oct 17, 9:30 am at Room 507
William Ballinger (Harvard University)
  
Oct 24, 2pm
Bryce Thomson (UC Davis)
  
Nov 7, 2pm
Abhishek Mallick (Dartmouth College)
  
Nov 14, 2pm
Oliver Thakar (Harvard University)
  
Nov 21, 2pm
Catherine Cannizzo (Columbia University)
  

 

Abstracts

Sep 19: Viktória Földvári (Columbia/Rényi Institute) "Legendrian Two-Bridge Knots"

Legendrian knots in contact 3-manifolds form a richer family than classical knots, as a given topological knot type may admit several distinct Legendrian realizations. A central question in the classification of Legendrian knots is whether a knot type is Legendrian simple, meaning uniquely determined by its classical invariants. While many examples are known, a full classification remains out of reach. I will present lower and upper bounds on the number of distinct Legendrian realizations of certain two-bridge knots with prescribed Thurston-Bennequin invariant, based on knot Floer homology and convex surface theory.

Sep 26: Randy Van Why (Georgia Tech) "Non-affine Stein manifolds and normal crossing divisors"

We construct a Stein manifold which may be compactified by a normal crossing divisor despite being neither affine nor quasi projective. We do this through the study of the symplectic and contact geometry of divisor neighborhoods. We show that the diffeomorphism type of a regular neighborhood of a compactifying normal crossing divisor is determined up to blow-up and blow-down by a natural contact structure on the boundary. This has implications for symplectic birational geometry and Stein fillable contact manifolds.