Israel Michael Sigal

Information for Students

Presently I am working in the following areas:

  1. Quantum Field Theory
    Consider a quantum system, such as a hydrogen atom, which is originally in an excited state. We expect such a system to emit photons and descend into its ground state. This is the process of radiation which in particular produces the light we see. We would like to develop mathematical understanding of the dynamics of this and similar processes.
  2. Nonlinear Partial Differential Equations of Quantum Physics
    Consider (non-integrable) evolution equations which have soliton solutions. Examples of such equations are nonlinear Schrödinger, Ginzburg-Landau, Landau-Lifshitz and Heisenberg ferromagnet equations to name just a few. One would like to understand solutions of such equations in a presence of inhomogeneities and/or describing several (interacting) solitons.
  3. Mathematical Biology
    Here we are interested in aggregation phenomena for living organisms, such as cells and bacteria (e.g. chemotaxis), and for proteins.
  4. Non-equilibrium Statistical Mechanics
    Quantum systems are never isolated but they interact with their environments. The latter can be assumed to be near their states of (local) equilibrium. The problem here is to describe the dynamics of such a coupled system. One would like to see in mathematically rigorous way how dynamics of isolated quantum systems is affected by interaction with its environment.