L1

  The intermediate state of a type-I superconductor is a classical example of energy-driven pattern-formation, first studied by Landau in 1937. Mathematically this can be modeled by a nonconvex functional with a singular perturbation, which physically represents the surface energy. In this talk I shall discuss how a combination of interpolation inequalities and explicit constructions permits to determine the scaling of the minimal energy with respect to the relevant material parameters, and therefore to predict a phase diagram for the observed microstructure. This talk is mainly based on joint work with Rustum Choksi, Robert V. Kohn, and Felix Otto.    

 

We will speak about the problem of classification of self-similar groups. The

main focus will be on groups generated by three-state  automata over an

alphabet on two letters. Numerous examples will be presented, as well as some

results concerning this class of groups.

 

 

I will talk about some ongoing work, motivated by a long standing problem in

the theory of dynamical systems. In particular, I will explain how p-adic

methods lead to the construction of elements in SL_n(Z) whose eigenvalues e_1,

., e_n generate a free abelian subgroup of rank n-1 in the multiplicative group

of positive real numbers. This is a special instance of a more general theorem,

asserting the existence of strongly hyperbolic elements in arithmetic subgroups

of SL_n(R).