4:00pm to 5:30pm  RH 440R  Logic Set Theory Ryan Sullivant  (UCI) Learning seminar: An introduction to large cardinals and L In this talk, we will cover the basics of measurable cardinals and their relationship to nontrivial elementary embeddings. We proceed with basic facts about the constructible universe, L. After laying this groundwork, we show L cannot have a measurable cardinal. Time permitting, we will discuss the dichotomy introduced by Jensen's covering lemma: either L is a good approximation to V, or there is a nontrivial elementary embedding from L to L.

4:00pm to 5:00pm  RH 306  Special Colloquium Mario Micheli  (Harvey Mudd College) Image processing in an undergraduate curriculum: ideas and experience for teaching and research In this talk I will illustrate my ideas and plans about the development of an undergraduate curriculum in the broader area of data science that includes, among other things, a course in image 
4:00pm to 5:00pm  RH 340P  Geometry and Topology Carolyn Abbott  (UC Berkeley) Ordering actions on hyperbolic metric spaces Every group admits at least one action by isometries on a hyperbolic metric space, and certain classes of groups admit many different actions on different hyperbolic metric spaces (in fact, often uncountably many). One such class of groups is the class of socalled acylindrically hyperbolic groups, which contains many interesting groups, such as mapping class groups, Out(F_n), and rightangled Artin and Coxeter groups, among many others. In this talk, I will describe how to put a partial order on the set of actions of a given group on hyperbolic spaces which, in some sense, measures how much information about the group the action provides. This partial order defines a "poset of actions" of the given group. I will then define the class of acylindrically hyperbolic groups and give some structural properties of the resulting poset of actions for such groups. In particular, I will discuss for which (classes of) groups the poset contains a largest element. 
11:00am to 12:00pm  RH 306P  Probability Yan Shuo Tan  (University of Michigan) Efficient algorithms for phase retrieval in high dimensions Mathematical phase retrieval is the problem of solving systems of rank1 quadratic equations. Over the last few years, there has been much interest in constructing algorithms with provable guarantees. Both theoretically and empirically, the most successful approaches have involved direct optimization of nonconvex loss functions. In the first half of this talk, we will discuss how stochastic gradient descent for one of these loss functions provably results in (rapid) linear convergence with high probability. In the second half of the talk, we will discuss a semidefinite programming algorithm that simultaneously makes use of a sparsity prior on the solution vector, while overcoming possible model misspecification. 
3:00pm to 4:00pm   Number Theory Oleksiy Klurman  (Royal Institute of Technology) Dynamical properties of multiplicative functions. Understanding joint behaviour of $(f(n),g(n+1))$ where f and g are given multiplicative functions play key role in analytic number theory with potentially profound consequences such as Riemann hypothesis, twin prime conjecture, Chowla's conjecture and many others. In the the first part of this talk, I will discuss joint work with A. Mangerel, answering an old question of Katai about distribution of points $\{(f(n),g(n+1))\}_{n\ge 1}\in \mathbb{T}^2,$ where f and g are unimodular multiplicative functions. In the second part of the talk, which is based on a joint work with P. Kurlberg, answering a question of M. Lemanczyk, we construct deterministic example of multiplicative function $f:{\mathbb{N}\to \{+1,1\}$ with various ergodic properties with respect to the Mirsky measure and discuss its relation to the interplay between Chowla conjecture and Riemann hypothesis.

4:00pm to 5:00pm  RH 306  Colloquium Distinguished Lecture by C. McMullen  (Harvard) The behavior of planes in confinement 
4:00pm to 5:00pm  RH 306  Distinguished Lectures Curt McMullen  (Harvard University) The behavior of planes in confinement 
1:00pm  rh 340N  Mathematical Physics Yinfun Shi  (Fudan University) Spectral gaps for quasiperiodic Schrodinger operators 
3:00pm to 4:00pm  NS2 2201  Distinguished Lectures Curt McMullen  (Harvard University) Quadrilaterals, billiards and moduli spaces 