## Introductory Remarks by Alondra Nelson

Alondra Nelson

IAS School of Social Science

November 6, 2019

Pedro Domingos

University of Washington

November 6, 2019

Mary Gray

Microsoft and Harvard University

November 6, 2019

Andrey Kupavskii

Member, School of Mathematics

November 5, 2019

Extremal set theory typically asks for the largest collection of sets satisfying certain constraints. In the first talk of these series, I'll cover some of the classical results and methods in extremal set theory. In particular, I'll cover the recent progress in the Erdos Matching Conjecture, which suggests the largest size of a family of k-subsets of an n-element set with no s pairwise disjoint sets.

Anna Gilbert

University of Michigan; Member, School of Mathematics

November 4, 2019

In this work, we exploit the ill-posedness of linear inverse

problems to design algoithms to release differentially private data or

measurements of the physical system. We discuss the spectral

requirements on a matrix such that only a small amount of noise is

needed to achieve privacy and contrast this with the poor conditioning

of the system. We then instantiate our framework with several

diffusion operators and explore recovery via l1 constrained

minimisation. Our work indicates that it is possible to produce

Sara Tukachinsky

Member, School of Mathematics

November 4, 2019

Open Gromov-Witten (OGW) invariants should count pseudoholomorphic maps from curves with boundary to a symplectic manifold, with various constraints on boundary and interior marked points. The presence of boundary poses an obstacle to invariance. In a joint work with J. Solomon (2016-2017), we defined genus zero OGW invariants under cohomological conditions.

Andrey Kupavskii

Member, School of Mathematics

October 29, 2019

Angel Martinez Martinez

Member, School of Mathematics

October 28, 2019

In this talk I will describe joint work with D. Alonso-Orán and A. Córdoba where we extend a result, proved independently by Kiselev-Nazarov-Volberg and Caffarelli-Vasseur, for the critical dissipative SQG equation on a two dimensional sphere. The proof relies on De Giorgi technique following Caffarelli-Vasseur intermingled with a nonlinear maximum principle that appeared later in the approach of Constantin-Vicol. The final result can be paraphrased as follows: if the data is sufficiently smooth initially then it is smooth for all times.