Sala Seminari (Dip. Matematica)

Seminario di Teoria dei numeri - Moduli di Iwasawa e valori speciali di L-funzioni

Relatore: 
Prof. Andrea Bandini

Abstract: numerose informazioni aritmetiche di grande interesse sono
rappresentate (almeno congetturalmente) da valori speciali di L-funzioni,
per esempio l'ordine del gruppo delle classi di un campo di numeri K
dalla zeta di Dedekind di K o il rango di una curva ellittica E dalla
L-funzione di E. La teoria di Iwasawa attraverso lo studio di alcuni
moduli (come i gruppi delle classi e i gruppi di Selmer) fornisce un
approccio algebrico alla costruzione di approssimazioni p-adiche delle

Data Seminario: 
Thursday, May 11, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
0000 - 17:00
Affiliazione: 
Università di Parma
Ora Inizio: 
0000 - 16:00

Regularization by noise in (2x 2) hyperbolic systems of conservation laws

Relatore: 
C. Olivera

In this talk we study a non-strictly hyperbolic system of conservation law by stochastic perturbation. We show existence and uniqueness of the solution. We do not assume BV-regularity for the initial conditions. The proofs are based on the concept of entropy solution and on the method of charactteristics (under the influence of noise). This is the first result on the regularization by noise in hyperbolic systems of conservation law.

Data Seminario: 
Tuesday, May 23, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
0000 - 12:15
Affiliazione: 
Universidade Estadual de Campinas
Ora Inizio: 
0000 - 11:15

Convergence of general weakly asymmetric exclusion processes

Relatore: 
K. Matetski

In my ongoing work with J. Quastel we consider spatially periodic growth models built from weakly asymmetric exclusion processes with finite jump ranges and general jump rates. We prove that at a large scale and after renormalization these processes converge to the Hopf-Cole solution of the KPZ equation driven by Gaussian space-time white noise. In contrast to the celebrated result by L. Bertini and G. Giacomin (in the case of the nearest neighbour interaction) and its extension by A. Dembo and L.-C.

Data Seminario: 
Tuesday, May 2, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
0000 - 12:15
Affiliazione: 
University of Toronto
Ora Inizio: 
0000 - 11:15

Strutture quasi complesse sulle sfere

Relatore: 
Maurizio Parton

"Una varietà complessa è una varietà il cui modello locale è C^n, invece che R^n. Tra le varietà compatte, l'esempio più semplice è probabilmente la sfera S^2 vista come spazio proiettivo complesso CP^1. Quali altre sfere ammmettono una struttura complessa? A tutt'oggi non è chiaro se esistono strutture complesse su S^6.

Data Seminario: 
Friday, April 28, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
0000 - 19:30
Affiliazione: 
Università di Chieti-Pescara
Ora Inizio: 
0000 - 18:30

Optimizing the fractional power of a Diffusion operator

Abstract. We study an optimization problem with SPDE constraints, which has the peculiarity that the control parameter $s$ is the $s$-th power of the diffusion operator in the state equation. Before moving to the SPDE case, we first describe the result of Sprekels-Valdinoci for the PDE case. Then we discuss a suitable concept of solutions of the state equation and establish pathwise differentiability properties of the stochastic process w.r.t. the fractional parameter $s$. Finally, we show that under certain conditions on the noise, optimality conditions for
Data Seminario: 
Wednesday, April 26, 2017
Relatore: 
Carina Geldhauser
Ora Fine: 
0000 - 18:00
Aula: 
Sala Seminari (Dip. Matematica)
Ora Inizio: 
0000 - 17:00

Scalar conservation laws with discontinuous flux

Relatore: 
Francesco Ghiraldin
Abstract. In the talk I will investigate the uniqueness of solutions of scalar conservation laws with discontinuous flux. While in the smooth setting this property follows from Kruzhkov's entropy inequalities, in the case of discontinuous fluxes these inequalities are not enough and additional dissipation conditions must be imposed at the discontinuity set of the flux. I will explain how any entropy solution admits traces on the discontinuity set of the flux field and use this to prove the validity of a generalized Kato inequality for any pair of solutions.
Data Seminario: 
Wednesday, May 3, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
0000 - 18:00
Affiliazione: 
Max Planck Institute Leipzig
Ora Inizio: 
0000 - 17:00

Numerical study of 1D optimal structures

Relatore: 
Edouard Oudet
Abstract. We focus our attention on shape optimization problems in which one dimensional connected objects are involved. Very old and classical problems in calculus of variation are of this kind: euclidean Steiner's tree problem, optimal irrigation networks, cracks propagation, etc. In a first part we quickly recall some previous work in collaboration with F. Santambrogio related to the functional relaxation of the irrigation cost. We establish a $\Gamma$-convergence of Modica and Mortola's type and illustrate its efficiency from a numerical point of
Data Seminario: 
Wednesday, April 19, 2017
Aula: 
Sala Seminari (Dip. Matematica)
Ora Fine: 
0000 - 19:00
Affiliazione: 
Université Grenoble Alpes
Ora Inizio: 
0000 - 18:00

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: 
0000 - 16:00
Affiliazione: 
Università di Pisa
Ora Inizio: 
0000 - 15:00

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