04/02/19  Seminario  14:30  15:30   Paolo SENTINELLI  Universidad de Chile, Santiago  The JonesWenzl idempotent of a generalized TemperleyLieb algebra
Given a finite dimensional generalized TemperleyLieb algebra, defined as a quotient of the Hecke algebra of a finite Coxeter group, we will define its JonesWenzl idempotente, in analogy with the classical case (type A).
In type B, these algebras have recently proved useful for the construction of knot invariants on the solid torus. On the other hand, in type A, the JonesWenzl idempotent appears in the construction of coloured Jones polynomials; thus one can believe that similar constructions can be found in type B or in other typer (where it makes sense to do some knot theory).
Taking into account a basis (the one indexed by the socalled fully commutative elements) which is seldom used in this context, we will show a way to obtain recursive formulas for the JonesWenzl idempotent, that are new even in the classical case, from which we shall deduce explicitly some coefficients of its expansion with respect to the above mentioned basis (namely, those related with the maxima of the minuscule quotients). These coefficients seem to be important in positive characteristic.

30/01/19  Seminario  16:30  17:30  1101 D'Antoni  Herve' Gaussier  Universita' di Grenoble  Complete Kaehler metrics with negative pinched holomorphic bisectional curvature on convex domains.
This is a joint work with Filippo Bracci and Andrew Zimmer.
We will give necessary conditions on the geometry of a convex domain D
for D to admit a complete Kaehler metric with negative pinched holomorphic bisectional curvature. 
30/01/19  Seminario  14:00  16:00  1201 Dal Passo  Edoardo Sernesi  Roma Tre  Curves on K3 Surfaces II [Lecture series in the framework of the Research Project "Families of curves: their moduli and their related varieties"  Mission Sustainability Tor Vergata, CUP: E8118000100005, Principal Investigator: F. Flamini]
 Generalities on BrillNoether theory. Lazarsfeld's proof of Petri's conjecture.  Gaussian maps, ribbons and extendability. Results of Wahl and BeauvilleMerindol.  The problem of characterizing K3 curves: some results.
[Lecture series in the framework of the Research Project "Families of curves: their moduli and their related varieties"  Mission Sustainability Tor Vergata, CUP: E8118000100005, Principal Investigator: F. Flamini 
29/01/19  Seminario  16:00  17:00  1101 D'Antoni  Adam Epstein  Universita' di Warwick  Transversality Principles in Holomorphic Dynamics
The moduli space of all degree D rational maps is
an orbifold of dimension 2D?2. We present a language for
describing dynamically natural subspaces, for example, the
loci of maps having
 specified critical orbit relations,
 cycles of specified period and multiplier,
 parabolic cycles of specified degeneracy and index,
 Herman ring cycles of specified rotation number,
or some combination thereof. We present a methodology for
proving the smoothness and transversality of such loci. The
natural setting for the discussion is a family of deformation
spaces arising functorially from first
principles in Teichmuller theory. Transversality ? flows from an
infinitesimal rigidity principle (following Thurston), in the corresponding
variational theory viewed cohomologically (following
KodairaSpencer). Results for deformation spaces may then be
transferred to moduli space. Moreover, the deformation space
formalism and associated transversality principles apply more
generally to finite type transcendental maps. 
29/01/19  Seminario  14:30  16:00  1201 Dal Passo  Giovanni Catino  Politecnico di Milano  Some canonical Riemannian metrics on four manifolds: existence and rigidity
In this talk I will present some results concerning rigidity and existence of canonical metrics on closed (compact without boundary) four manifolds. In particular I will consider Einstein metrics, Harmonic Weyl metrics and some generalizations. These are joint works with P. Mastrolia (UniMI), D.D. Monticelli and F. Punzo (Polimi). 
28/01/19  Seminario  14:30  15:30  1201 Dal Passo  Paolo LIPPARINI  Università di Roma "Tor Vergata"  Introduction to universal algebra
I will present a brief overview of some classical results in universal algebra, trying to stress the links with the study of algebra in a more "classical" sense, or the lack of such links.
Time permitting, I will consider some more recent developments, such as commutator theory and Hobby and McKenzie's classification of finite algebraic structures. 
24/01/19  Seminario  12:00  13:00  1101 D'Antoni  Isabella Furci  Università degli Studi dell'Insubria  Spectral analysis and fast methods for structured matrix sequences and PDE discretizations
When simulating phenomena in applied sciences, often one has to deal with functional equations that do not admit an analytical solution. Describing real situations is however possible resorting to numerical approximations. The general purpose is to furnish useful tools aimed at solving computational issues, stemming from such approximation techniques.
In this talk we focus on the case where the resulting matrix sequences ${A_n}_{n}$ possess a structure, that is they belong to the class of Toeplitz matrix sequences or to the more general class of emph{Generalized Locally Toeplitz (GLT)} matrix sequences. Consequently, the spectral analysis of the coefficient matrices plays a crucial role for an efficient and fast resolution.

23/01/19  Seminario  14:00  16:00  1101 D'Antoni  Edoardo Sernesi  Roma Tre  Curves on K3 Surfaces I [Lecture series in the framework of the Research Project "Families of curves: their moduli and their related varieties"  Mission Sustainability Tor Vergata, CUP: E8118000100005, Principal Investigator: F. Flamini]
 Generalities on BrillNoether theory. Lazarsfeld's proof of Petri's conjecture.
 Gaussian maps, ribbons and extendability. Results of Wahl and BeauvilleMerindol.
 The problem of characterizing K3 curves: some results.
[Lecture series in the framework of the Research Project "Families of curves: their moduli and their related varieties"  Mission Sustainability Tor Vergata, CUP: E8118000100005, Principal Investigator: F. Flamini] 
21/01/19  Seminario  16:00  17:00  1101 D'Antoni  Sam GUNNINGHAM  University of Edinburgh  Quantum character theory
I will give an overview of various approaches to studying character varieties (moduli spaces of local systems on manifolds) using tools of geometric representation theory and topological field theory. For example, in my work with BenZvi and Nadler we show that the homology groups of character varieties (which are the subject of fascinating conjectures of Hausel and Rodriguez Villegas) are extracted from a certain topological field theory associated to the monoidal category of HarishChandra bimodules. A closely related topological field theory constructed by BenZvi, Brochier, and Jordan defines canonical quantization of character varieties associated to the quantum group; in my ongoing work with David Jordan we are investigating how this theory computes invariants of knots and skeins in 3manifolds via qanalogues of character sheaves and HarishChandra bimodules.
I will not assume any priori familiarity with any of these concepts. 
15/01/19  Seminario  16:00  17:00  1101 D'Antoni  Andrew Zimmer  Louisiana State University  Two boundary rigidity results for holomorphic
In this talk we discuss two boundary versions of the Schwarz lemma. The first is
for general holomorphic self maps of bounded convex domains with C^2 boundary.
The second is for biholomorphisms of domains who have an invariant Kahler metric with bounded
sectional curvature. The proof of the first relies on some new results about the boundary
values of complex geodesics. The proof of the second uses many techniques from Riemannian
Geometry: the dynamical behavior of the geodesic flow, deforming metrics using the Ricci
flow, injectivity radius estimates, etc. 