Events

Algebra/Topology Seminar – Austin Christian (Georgia Tech)

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Title: Symplectic fillings of lens spaces Abstract: Many contact 3-manifolds arise as boundaries of symplectic 4-manifolds, and we are often interested in the filling problem for a given contact 3-manifold.  That is, how many symplectic 4-manifolds have the given contact boundary?  This problem has previously been solved for standard contact structures on lens spaces.  We use

Applied Math Seminar – Youngjoon Hong (Sungkyunkwan University, Korea)

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Title: Deep neural network and numerical analysis - adversarial attack on image and videos Abstract: Deep neural networks have achieved state-of-the-art performance in a variety of fields. The exponential growth of machine learning models and the extreme success of deep learning have seen application across a multitude of disciplines. Recent works observe that a class of

Algebra/Topology Seminar – Alberto Cavallo (CIRGET/Renyi Institute)

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Title: Slice links and smooth 4-manifolds Abstract: We vary the trace embedding lemma in order to prove results about smooth, closed, simply connected 4-manifolds, studying smoothly slice links in them. We focus on homotopy 4-spheres, which are potential counterexamples to the smooth 4-dimensional Poincaré conjecture. In particular, we split them, as for exotic R^4's,  in large and

Algebra/Topology Seminar – Orsola-Capovilla Searle (UC Davis)

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Title: Infinitely many Lagrangian Tori in Milnor fibers constructed via Lagrangian Fillings of Legendrian links Abstract: One approach to studying symplectic manifolds with contact boundary is to consider Lagrangian submanifolds with Legendrian boundary; in particular, one can study exact Lagrangian fillings of Legendrian links. There are still many open questions on the spaces of exact Lagrangian fillings

Algebra/Topology Seminar – Johnny Nicholson (Imperial College)

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Title: The homotopy type of a finite 2-complex with non-minimal Euler characteristic Abstract: Two presentations for a group G which have the same deficiency are called exotic if the corresponding presentation complexes are not homotopy equivalent. The first examples of exotic presentations were found by Dunwoody and Metzler in the 1970s but, owing to the difficulty of

Analysis Seminar – Simon Bortz (University of Alabama)

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Title: A free boundary problem for the heat equation. Abstract: In his breakthrough result, it was shown by Dahlberg that the L^2 Dirichlet problem for the Laplacian (harmonic functions) is solvable in the region above a Lipschitz graph. Dahlberg did this by showing a local reverse Hölder inequality for the Poisson kernel in such domains.

Analysis Seminar – Armin Schikorra (University of Pittsburgh)

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Title: A Harmonic Analysis perspective on $W^{s,p}$ as $s \to 1^-$. Abstract: We revisit the Bourgain-Brezis-Mironescu result that the Gagliardo-Norm of the fractional Sobolev space W^{s,p}, up to rescaling, converges to W^{1,p} as s\to 1. We do so from the perspective of Triebel-Lizorkin spaces, by finding sharp $s$-dependencies for several embeddings between $W^{s,p}$ and $F^{s,p}_q$

Analysis Seminar – Ryan Alvarado (Amherst College)

346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United States

Title: Optimal embeddings and extensions for Triebel-Lizorkin and Besov spaces in spaces in quasi-metric measure spaces. Abstract: Embedding and extension theorems for certain classes of function spaces in $\mathbb{R}^n$ (such as Sobolev spaces) have played a fundamental role in the area of partial differential equations. In this talk, we will discuss some recent work which