## Nuclear Policy in the age of Putin and Xi

Walter B. Slocombe

May 15, 2019

Tarek Elgindi

University of California, San Diego

May 6, 2019

We describe a recent construction of self-similar blow-up solutions of the incompressible Euler equation. A consequence of the construction is that there exist finite-energy $C^{1,a}$ solutions to the Euler equation which develop a singularity in finite time for some range of $a>0$. The approach we follow is to isolate a simple non-linear equation which encodes the leading order dynamics of solutions to the Euler equation in some regimes and then prove that the simple equation has stable self-similar blow-up solutions.

Scott Tremaine

Richard Black Professor, School of Natural Sciences

May 3, 2019

Sabine Schmidtke

School of Historical Studies

May 2, 2019

A talk by Sabine Schmidtke at the occasion of the spring meeting of the IAS Board of Trustees (May 2019)

Thomas Haines

University of Maryland

May 2, 2019

The singularities in the reduction modulo $p$ of the modular

curve $Y_0(p)$ are visualized by the famous picture of two curves

meeting transversally at the supersingular points. It is a fundamental

question to understand the singularities which arise in the reductions

modulo $p$ of integral models of Shimura varieties. For PEL type

Shimura varieties with parahoric level structure at $p$, this question

has been studied since the 1990's. Due to the recent construction of

Mirjam Cvetic

University of Pennsylvania

April 29, 2019

We present recent advances in constructions of globally consistent

F-theory compactifications with the exact chiral spectrum of the minimal

supersymmetric Standard Model. We highlight the first such example and

then turn to a subsequent systematic exploration of the landscape of

F-theory three-family Standard Models with a gauge coupling unification.

Employing algebraic geometry techniques, all global consistency

conditions of these models can be reduced to a single criterion on the

Clay Cordova

Member, School of Natural Sciences, IAS

April 26, 2019

Anomalies are invariants under renormalization group flow which lead to powerful constraints on the phases of quantum field theories. I will explain how these ideas can be generalized to families of theories labelled by coupling constants like the theta angle in gauge theory. Using these ideas we will be able to prove that certain systems, such as Yang-Mills theory in 4d, necessarily have a phase transition as these parameters are varied. We will also show how to use the same ideas to constrain the dynamics of defects where coupling constants vary in spacetime.

Phyllis Lambert Charles Scribner III Frank Gehry Jack Freiberg David A. Levine Horst Bedekamp

April 26, 2019

Phyllis Lambert Charles Scribner III Nicola Courtright Jack Freiberg David A. Levine Frank Gehry Horst Bedekamp

April 26, 2019