|20/03/20||Seminario||15:00||16:00||Aula Gismondi||Sebastiano CARPI||Università di Roma ||Weak quasi-Hopf algebras, vertex operator algebras and conformal nets
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(see the instructions in the abstract)
Weak quasi-Hopf algebras give a generalization of Drinfeld's quasi-Hopf algebras. They were introduced by Mack and Schomerus in the early nineties in order to describe quantum symmetries of certain conformal field theories. Every fusion category is tensor equivalent to the representation category of a weak quasi-Hopf algebra. In particular the representation categories arising from rational conformal field theories such as the representation categories of strongly rational vertex operator algebras or of completely rational conformal nets can be described and studied by means of weak quasi-Hopf algebras.
In this talk I will discuss some aspects of the theory of weak quasi-Hopf algebras in connection with vertex operator algebras and conformal nets and explain some applications.
Based on a joint work in preparation with S. Ciamprone and C. Pinzari.
the talk will be held in streaming, as a videoconference on-line; in order to join the videoconference, go
and click on the link that you find there.
|13/03/20||Seminario||14:30||15:30||1101 D'Antoni||Mario MARIETTI||Università Politecnica delle Marche - Ancona||Weak generalized lifting property, Bruhat intervals and Coxeter matroids
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A natural generalization of the concept of a matroid is the concept of a Coxeter matroid, which was introduced by I. Gelfand and V. Serganova in 1987. In this talk, we will present a result stating that the Bruhat intervals of any arbitrary finite Coxeter group are Coxeter matroids. The main tool for proving this result is a new property, the weak generalized lifting property, which holds for all (finite and infinite) Coxeter groups and may have interest in its own right.
This is based on joint work with F. Caselli and M. D'Adderio.
|06/03/20||Seminario||15:15||16:15||1101 D'Antoni||Andreas Knutsen||Bergen University||Moduli of polarized Enriques surfaces
Moduli spaces of polarized Enriques surfaces have several irreducible components, even if one fixes the degree of the polarization. I will present some results concerning these spaces. In particular I will answer a question of Gritsenko and Hulek concerning connectedness of the étale double covers from the moduli spaces of polarized Enriques surfaces to the moduli spaces of numerically polarized such surfaces, and I will give a way to determine all irreducible components of these moduli spaces. This talk is part of the activity of the MIUR Excellence Department Project CUP E83C18000100006.
|28/02/20||Seminario||15:15||16:15||1101 D'Antoni||Laura Pertusi||Università di Milano||Stability conditions on Gushel-Mukai varieties
A generic Gushel-Mukai variety X is a quadric section of a linear section of the Grassmannian Gr(2,5). Kuznetsov and Perry proved that the bounded derived category of X has a semiorthogonal decomposition with exceptional objects and a non-trivial subcategory Ku(X), known as the Kuznetsov component. In this talk we will discuss the construction of stability conditions on Ku(X) and, consequently, on the bounded derived
category of X. As applications, for X of even-dimension, we will construct locally complete families of hyperkaehler manifolds from moduli spaces of stable objects in Ku(X) and we will determine when X has a homological associated K3 surface. This is a joint work with Alex Perry and Xiaolei Zhao.
|28/02/20||Seminario||14:00||15:00||1101 D'Antoni||Marco D'ANNA||Università di Catania||Almost Gorenstein rings and further generalizations: the 1-dimensional case
I will present the class of almost Gorenstein rings, with focus onto 1-dimensional (commutative, unital) local rings. This class of rings, introduced (by Barucci and Froberg) for algebroid curves, and recently extended (by Goto and others) to more general 1-dimensional rings, and late on in dimension greater than 1, has been intensively studied in the last years. In the 1-dimensional case definitions of other classes of rings have later been suggested that generalize Gorenstein rings and almost Gorenstein rings from different point of view: in particular, I will discuss one of them, which is motivated by the relations between the properties of the ring (R,m) and those of the R-algebra m:m in Q(R).
This is (partially) a joint work with Francesco Strazzanti.
|25/02/20||Seminario||14:30||15:29||1101 D'Antoni||Marco Cirant||Università di Parma||Multi-agent optimal control and mean field limits with density constraints
The talk will be devoted to the analysis of a variational problem that describes the optimal evolution of a probability measure, subject to density constraints and nonlocal potential of Riesz type. The problem arises in the study of some first order Mean Field type control problems, with density constraints and aggregating interactions. Under suitable symmetry assumptions, I will discuss the existence of periodic orbits, and their convergence to heteroclinics, which connect different ground states of the stationary problem in an infinite time horizon. Finally, I will discuss some qualitative properties of the discrete counterpart of the problem, which involves the optimal evolution of a finite number of particles that are subject to distance constraints.
|21/02/20||16:00||18:00||1201 Dal Passo||Yasuyuki Kawahigashi||University of Tokyo ||"Relative boundary-bulk duality and orbifold subfactors" Minicorso di Dottorato - quarta e quinta lezione|
|21/02/20||Seminario||14:00||15:00||1101 D'Antoni||Alessandro D'ANDREA||“Sapienza” Università di Roma||Irreducible representations of primitive Lie pseudoalgebras of type H
Lie pseudoalgebras are a “multivariable” generalization of Lie algebras. Their classification follows Cartan’s 1909 classification of simple infinite dimensional linearly compact Lie algebras, in terms of four infinite families, called of type W, S, K and H. Finite irreducible representations in type W, S and K have already been classified by exploiting a common strategy, which, however, remarkably fails, in multiple points, in case H. In this talk I will explain all of the above issues and how to obtain a classification in type H as well.
This is a joint work with B. Bakalov and V. G. Kac.
|19/02/20||16:00||18:00||1201 Dal Passo||Yasuyuki Kawahigashi||University of Tokyo ||"Relative boundary-bulk duality and orbifold subfactors"
Minicorso di Dottorato - seconda e terza lezione|
|18/02/20||Seminario||16:00||17:00||1201 Dal Passo||Karen Strung||The Czech Academy of Sciences||The classification programme for C*algebras and its interactions with topological dynamics|
The classification programme has determined that infinite dimensional simple separable unital C*-algebras with finite nuclear dimension can be classified by the so-called “Elliott Invariant”, under
the mild assumption that they satisfy the UCT. It becomes an interesting question to determine what classes of “naturally occurring” C*-algebras
are covered by the classification, as well as the range of the invariant for such classes. I will discuss C*-algebras arising from topological
dynamical systems and their relation to the classification program for C*-algebras.