Seminars

The Mathematical Physics sector runs the following general seminars:

and more specific seminars for the different research areas of the sector:

There are also:

If you are going to speak in a seminar you can find some useful information here.

Upcoming seminars

When Where Who Title (Click for abstract)


Past seminars 2013

When Where Who Title (Click for abstract)
Wed 16 Jan 2013 16:30 Santorio, room 136 Elisa Tenni (SISSA) Clifford theorem for singular curves and some applications
Abstract. Abstract: I will discuss a generalization of the classical Clifford's theorem to singular curves, reducible or non reduced.
I will prove that for 2-connected curves a Clifford-type inequality holds for a vast set of torsion free rank one sheaves. I intend to show that our assumptions on the sheaves are the most natural when working with this kind of results.
I will moreover show that this result has many applications to the study of the canonical morphism of a singular curve, in particular that it implies a generalization of the classical Noether's theorem to 3-connected curves.
This is a joint work with M. Franciosi.
Mon 14 Jan 2013 16:00 Santorio, room 136 Kurusch Ebrahimi Fard (Instituto de Ciencias Matemáticas (Madrid)) Exponential renormalization
Abstract. Abstract: In this talk we introduce the so-called exponential renormalization method, developed in the context of the Connes-Kreimer Hopf algebra of Feynman graphs. Using Dyson's identity for Green's functions as well as the link between the Faà di Bruno Hopf algebra and Hopf algebras of Feynman graphs, its relation to the composition of formal power series is analyzed. This leads to the introduction of the notion of counterfactors and order n bare coupling constants. Eventually we analyze the role of the Rota-Baxter property for renormalization scheme maps.

KEF, F. Patras: "Exponential renormalization", Ann. Henri Poincaré 11 (2010), 943-971; "Exponential Renormalization II: Bogoliubov's R-operation and momentum subtraction schemes", J. Math. Phys. 53, 083505 (2012).
Thu 10 Jan 2013 16:30 Santorio, room 136 Prof. Giovanni Marelli (Universidad de Antioquia, Medellin, Colombia) Gradient-like vector fields on a complex analytic variety
Abstract. Given a complex analytic function $f$ on a Whitney stratified complex analytic variety of complex dimension $n$, whose real part $Re(f)$ is Morse, we prove the existence of a stratified gradient-like vector field for $Re(f)$ such that the unstable set of a critical point $p$ on a stratum $S$ of complex dimension $s$ has real dimension $m(p)+n-s$, where $m(p)$ is the Morse index of the restriction of $f$ to $S$, as was conjectured by Goresky and MacPherson. We expect as application the construction of the Morse-Witten complex for intersection homology.
Wed 9 Jan 2013 16:30 Santorio, room 136 Dr. Ada Boralevi (SISSA) Spaces of matrices of constant rank and instantons
Abstract. Abstract: Given a complex vector space V of dimension n, one can look
at d-dimensional linear subspaces A in \Wedge^2(V), whose elements
have constant rank r. The natural interpretation of A as a vector
bundle map yields some restrictions on the values that r,n and d can
attain. After a brief overview of the subject and of the main
techniques used, I will concentrate on the case r=n-2 and d=4. I will
introduce what used to be the only known example, by Westwick, and
give an explanation of this example in terms of instanton bundles and
the derived category of P^3. I will then present a new method that
allows to prove the existence of new examples of such spaces, and show
how this method applies to instanton bundles of charge 2 and 4. These
results are in collaboration with D.Faenzi and E.Mezzetti.