We demonstarte that in rough quantum billiards, the memory of the initial conditions is governed by a single universal energy-dependent parameter---one of the inverse participation ratios---that governs all functions of the to-be-destroyed integrals of motion as observables and all eigenstates of the to-be-perturbed integrable system as the initial states
In physics, the main objective in spin glasses is to understand
the strange magnetic properties of alloys.
Yet the models invented to explain the observed phenomena are of a rather
fundamental nature in mathematics. In this talk, we will focus on one of the most important mean field
models,
called the Sherrington-Kirkpatrick model,
and discuss its disorder chaos problem. Using Guerra's replica
symmetric-breaking bound, we present a mathematically rigorous proof for this problem.
Given a lightface $\Sigma^1_2$ set of reals A we present the construction of a tree on $\omega\times\omega_1$ such that A is the projection of T. Moreover, the tree T is an element of any transitive model of ZF-PowerSetAxiom that has $\omega_1$ as element.
In the talk we address a system of PDEs describing an
interaction between an incompressible fluid and an elastic
body. The fluid motion is modeled by the Navier-Stokes
equations while an elastic body evolves according to an
linear elasticity equation. On the common boundary, the
velocities and stresses are matched. We discuss available
results on local well-posedness and prove new existence and
uniqueness results with the velocity and the displacement
belonging to low regularity spaces.
We present a bound on the integral of the velocity of a planar Jordan curve in the interior of another Jordan curve. We then apply this bound to verify a new Poincare-Bendixson type result for planar infinite-horizon optimal control.
A smooth metric space is a Riemanian manifold together with a weighted volume. It is naturally associated with a weighted Laplacian. In this talk, I will discuss some recent results about function theoretic and spectral propeties of the weighted Laplacian and volume estimates for the volume and weighted volume. The results can be applied to study the shrinking gradient Ricci solitons and self-shrinker for mean curvature flows.
In most practical applications of fluid mechanics, it is the interaction of the fluid with the boundary that is most critical to understanding the behavior of the fluid. Physically important parameters, such as the lift and drag of a wing, are determined by the sharp transition the air makes from being at rest on the wing to flowing freely around the airplane near the wing. Mathematically, the behavior of such flows are modeled by the Navier-Stokes equations. In this talk, I will discuss the asymptotic behavior of solutions to the Navier-Stokes equations at small viscosity under various boundary conditions.