4:00pm to 5:00pm  RH306  Applied and Computational Mathematics Xuehai Huang  (Wenzhou University) Decoupling of Mixed Methods Based on General Helmholtz Decompositions A framework to systematically decouple high order elliptic equations into combination of Poissontype and Stokestype equations is developed using the tools of differential complexes and Helmholtz decompositions. The key step is to systematically construct the underling commutative diagrams involving the complexes and Helmholtz decompositions in a general way. Discretizing the decoupled formulation leads to a natural superconvergence between the Galerkin projection and the decoupled approximation. Examples include but not limit to: the primal formulations and mixed formulation of biharmonic equation, fourth order curl equation, and triharmonic equation etc. As a byproduct, Helmholtz decompositions for many dual spaces are obtained. 
4:00pm to 5:30pm  RH 440R  Logic Set Theory Zach Norwood  (UCLA) Coding along trees and remarkable cardinals A major project in set theory aims to explore the connection between large cardinals and socalled generic absoluteness principles, which assert that forcing notions from a certain class cannot change the truth value of (projective, for instance) statements about the real numbers. For example, in the 80s Kunen showed that absoluteness to ccc forcing extensions is equiconsistent with a weakly compact cardinal. More recently, Schindler showed that absoluteness to proper forcing extensions is equiconsistent with a remarkable cardinal. (Remarkable cardinals will be defined in the talk.) Schindler's proof does not resemble Kunen's, however, using almostdisjoint coding instead of Kunen's innovative method of coding along branchless trees. We show how to reconcile these two proofs, giving a new proof of Schindler's theorem that generalizes Kunen's methods and suggests further investigation of nonthin trees. 
4:00pm to 5:00pm  RH 340P  Geometry and Topology Qiongling Li  (Caltech) Hodge metric of nilpotent Higgs bundles On a complex manifold, a Higgs bundle is a pair containing a holomorphic vector bundle E and a holomorphic End(E)valued 1form. In this talk, we focus on nilpotent Higgs bundles, for example, the ones arising from variations of Hodge structures for a deformation family of Kaehler manifolds. We first give an optimal upper bound of the curvature of Hodge metric of the deformation space of CalabiYau manifolds. Secondly, we prove a rigidity theorem of the holonomy of polystable nilpotent Higgs bundles via the nonabelian Hodge theory when the base manifold is a Riemann surface. This is joint work with Song Dai. 
3:00pm to 4:00pm  RH 306  Nonlinear PDEs Jeremy LeCrone  (University of Richmond) Mean Value Theorems for Riemannian Manifolds via the Obstacle Problem In this talk, I will discuss recent results produced with coauthors Ivan Blank (KSU) and Brian Benson (UCR) regarding a formulation of the Mean Value Theorem for the LaplaceBeltrami operator on smooth Riemannian manifolds. We define the sets upon which mean values of (sub)harmonic functions are computed via a particular obstacle problem in geodesic balls. I will thus begin by discussing the classical obstacle problem and then an intrinsic formulation on manifolds developed in our recent paper. After demonstrating how the theory of obstacle problems is leveraged to produce our Mean Value Theorem, I will discuss local and global theory for our family of mean value sets and potential connections between the properties of these sets and the geometry of the underlying manifold. 
4:00pm to 5:00pm  RH 306  Differential Geometry Dan Knopf  (UT Austin) NonKahler Ricci flow singularities that converge to KahlerRicci solitons We describe Riemannian (nonKahler) Ricci flow solutions that develop finitetime TypeI singularities whose parabolic dilations converge to a shrinking Kahler–Ricci soliton singularity model. More specifically, the singularity model for these solutions is the “blowdown soliton” discovered in 2003 by Feldman, Ilmanen, and the speaker. Our results support the conjecture that the blowdown soliton is stable under Ricci flow. This work also provides the first set of rigorous examples of nonKahler solutions of Ricci flow that become asymptotically Kahler, in suitable spacetime neighborhoods of developing singularities, at rates that break scaling invariance. These results support the conjectured stability of the subspace of Kahler metrics under Ricci flow. 
2:00pm  RH 340P  Mathematical Physics Christoph Marx  (Oberlin) Dependence of the density of states on the probability distribution for discrete random Schrödinger operators We prove the Höldercontinuity of the density of states measure (DOSm) and the integrated density of states (IDS) for discrete random Schrödinger operators with finiterange potentials with respect to the probability measure. In particular, our result implies that the DOSm and the IDS for smooth approximations of the Bernoulli distribution converge to the corresponding quantities for the BernoulliAnderson model. Other applications of the technique are given to the dependency of the DOSm and IDS on the disorder, and the continuity of the Lyapunov exponent in the weakdisorder regime for dimension one. The talk is based on joint work with Peter Hislop (Univ. of Kentucky) 
3:00pm to 4:00pm  RH 306  Number Theory Sean Howe  (Stanford University) Sideways KatzSarnak and motivic random variables A fundamental observation in KatzSarnak's study of the zero spacing of Lfunctions is that Frobenius conjugacy classes in suitable families of varieties over finite fields approximate infinite random matrix statistics. For example, the normalized Frobenius conjugacy classes of smooth plane curves of degree d over F_q approach the Gaussian symplectic ensemble as we take first q to infinity, then d to infinity. In this talk, we explain a sideways version of this result where the limits in d and q are exchanged, and give a Hodge theoretic analog in characteristic zero. 
4:00pm to 6:00pm  NS II 1201  Colloquium Barry Simon  (Caltech) More tales of our fathers This is not a mathematics talk but it is a talk for mathematicians. Too often, we 
11:00am to 12:00pm  340P  Applied and Computational Mathematics Zhaosong Lu  (Simon Fraser University) Algorithmic Development for Computing Bstationary Points of a Class of Nonsmooth DC Programs In the first part of this talk, we study a convexconstrained nonsmooth DC program In the second part we consider a class of DC constrained nonsmooth DC programs. We propose penalty and This is joint work with Zhe Sun and Zirui Zhou. 
4:00pm  MSTB 120  Graduate Seminar SongYing Li  (UC Irvine) Characterizations of the unit ball in Euclidean spaces. In this talk, I will give you many ways to characterize the unit ball in $R^n$ or in $C^n$. It involves, differential equations, first eigenvalue of LaplaceBeltrami operator, etc.
