Sala Seminari (Dip. Matematica)

Embedding arithmetic hyperbolic manifolds

Tipo Seminario: 
Relatore: 
Leone Slavich

Given an n-dimensional hyperbolic manifold M, it is reasonable to ask whether or not it can be realized as a totally geodesic, embedded submanifold of an (n+1)-dimensional hyperbolic manifold. If this is true, we say that M geodesically embeds. Determining whether or not a hyperbolic manifolds geodesically embeds is, in general, quite difficult.

However, if we restrict our attention to the case of arithmetic manifolds of simplest type, (a class of manifolds constructed using tools from number theory), we can show that, in many cases, they do indeed embed geodesically.

Data Seminario: 
Wednesday, April 5, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 15:00
Affiliazione: 
Università di Pisa
Ora Inizio: 
Saturday, January 1, 0000 - 14:00

Seminario di Teoria dei numeri - On some algebraic properties of the locally free class group

Relatore: 
Dott.Reynold Fregoli

Abstract:
Let N/K be a normal tame extension of number fields and let G := Gal(N/K)
be its Galois group. It is common knowledge that, under these conditions,
[O_N] lies in the locally free class group Cl(O_K[G]). What can be said about
the existence of a normal integral basis for the extension N/K, by knowing
the structure of the group Cl(O_K[G])? In some cases this problem is easily
settled via cancellation law.
There is also a rank notion for locally free modules over orders. Which

Data Seminario: 
Tuesday, April 4, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Inizio: 
Saturday, January 1, 0000 - 15:00
Ora Fine: 
Saturday, January 1, 0000 - 16:00

Topological and holomorphic disk filling

Relatore: 
Roberta Maccheroni

In this talk I’ll describe the problem of filling submanifolds with topological or holomorphic disks. The case of geodesics on compact Riemannian surfaces with nonpositive scalar curvature will be treated. I will prove non existence of such disk filling, using several different tecniques. Two possible generalizations in higher dimension will be shown:

– the product of geodesics on the product of compact Riemannian surfaces with nonpositive scalar curvature does not admit a holomorphic disk filling;

Data Seminario: 
Friday, March 31, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 14:30
Affiliazione: 
Università di Parma
Ora Inizio: 
Saturday, January 1, 0000 - 13:30

Some results on focusing Mean Field Games

Relatore: 
Marco Cirant
Abstract. Mean Field Game (MFG) theory is the study of strategic decision making in a very large population of small interacting individuals. We consider models where agents prefer clustering in high-density areas. The goal is to understand the existence of smooth solutions to the corresponding MFG system of coupled ergodic Hamilton-Jacobi-Bellman and Kolmogorov equations.
Data Seminario: 
Wednesday, April 19, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 17:00
Affiliazione: 
Universita' di Padova
Ora Inizio: 
Saturday, January 1, 0000 - 16:00

Anisotropic energies in Geometric Measure Theory.

Relatore: 
Antonio De Rosa

Abstract. 

We present our recent extension of Allard’s celebrated rectifiability theorem to the setting of varifolds with locally bounded first variation with respect to an anisotropic integrand. In partic- ular, we identify a necessary and sufficient condition on the integrand to obtain the rectifiability of every d-dimensional varifold with locally bounded first variation and positive d-dimensional density. In codimension one, this condition is shown to be equivalent to the strict convexity of the integrand with respect to the tangent plane.

Data Seminario: 
Wednesday, March 29, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 17:00
Affiliazione: 
Universita' di Zurigo
Ora Inizio: 
Saturday, January 1, 0000 - 16:00

Stable classification of four Manifolds

Relatore: 
Riccardo Pedrotti

The classification of smooth four manifolds up to diffeomorphism is one of nightmares of a Topologist: it’s known to be impossible (it would solve the Word Problem) in full generality, but for certain classes of fundamental groups there are important results mainly due to Freedman. If we allow more relaxed notions of classification then much more can be said and computed.

Data Seminario: 
Thursday, March 16, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 18:30
Affiliazione: 
University of Bonn
Ora Inizio: 
Saturday, January 1, 0000 - 17:30

An introduction to the Kuramoto model for synchronization

Tipo Seminario: 
Relatore: 
Debota Amadori
We consider the Kuramoto model, originally proposed to describe a set of N oscillators coupled through their phase, and its kinetic version obtained in the mean-field limit. After a review of the basic properties of the discrete system, we will address some results from the literature about the large-time behavior of solutions for the kinetic equation. In the case of identical oscillators, a full description is available ([1]). For the case of non-identical oscillators, sufficient conditions lead to the phase concentration (see for instance [2]).
Data Seminario: 
Wednesday, April 5, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 17:30
Affiliazione: 
universita' de L'Aquila
Ora Inizio: 
Saturday, January 1, 0000 - 16:00

Entropy and length rigidity of negatively curved manifolds of finite volume

Tipo Seminario: 
Relatore: 
Andrea Sambusetti

The problems of conjugacy rigidity and of entropy rigidity have a long history, with major breakthroughs in the last twenty years, for negatively curved compact manifolds and symmetric spaces. On the other hand, little is known for finite volume manifolds. I will survey the state of the art of these problems, and explain what can be generalized to finite volume manifolds, pointing out the main difficulties that arise in the non-compact case.

Data Seminario: 
Wednesday, March 22, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
Saturday, January 1, 0000 - 15:00
Affiliazione: 
Roma La Sapienza
Ora Inizio: 
Saturday, January 1, 0000 - 14:00

Pages

Subscribe to Sala Seminari (Dip. Matematica)