Notiziario Scientifico

Notiziario dei seminari di carattere matematico
a cura del Dipartimento di Matematica G. Castelnuovo
Sapienza Università di Roma

Settimana dal 22 al 28 ottobre 2018


Lunedì 22 ottobre 2018
Ore 14:15, aula di Consiglio
seminario di Analisi Matematica
Michiel Bertsch (Universita' di Roma Tor Vergata e IAC-CNR)
Travelling wave solutions of a system of PDEs (a bit beyond Fisher-KPP)
The structure and stability of the travelling waves of the Fisher-KPP equation are very well known. The solutions satisfy a dynamical system in the phase plane. In the seminar I shall consider a related dynamical system in 3D. Its solutions are travelling waves of a system of evolution equations. I shall discuss their structure, and present some open problems, mainly concerning their stability.


Lunedì 22 ottobre 2018
Ore 16:00, aula Dal Passo, dipartimento di Matematica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1
seminario
Layla SORKATTI (Al-Neelain University, Khartoum)
Symplectic alternating algebras
We first give some general overview of symplectic alternating algebras and then focus in particular on the structure and classification of nilpotent symplectic alternating algebras. N.B.: this talk is part of the activity of the MIUR Excellence Department Project CUP E83C18000100006


Martedì 23 ottobre 2018
Ore 14:30, aula 311, Pal. C, Dipartimento di Matematica e Fisica, Università di Roma Tre, largo san Leonardo Murialdo 1
seminario di Fisica Matematica
Prof. Clement Erignoux (Universita' di Roma Tre)
Hydrodynamics for a non-ergodic activated exclusion process
The Entropy Method introduced by Guo, Papanicolaou and Varadhan (1988) has been used with great sucess to derive the scaling hydrodynamic behavior of wide ranges of conserved lattice gases (CLG). It requires to estimate the entropy of the measure of the studied process w.r.t. some nice, usually product, measure. In this talk, I will present an exclusion model inspired by a model introduced by Goncalves, Landim, Toninelli (2008), with a dynamical constraint, where a particle at site x can only jump to x+delta iff site x-delta (delta=pm1) is occupied as well. I will give some insight on the different microscopic and macoscopic situations that can occur for this model, and briefly describe the steps to derive the hydrodynamic limit for this model by adapting the Entropy Method to non-product reference measures. I will also expand on the challenges and question raised by this model and on some of its nice mapping features. Joint work with O. Blondel, M. Sasada, and M. Simon.


Mercoledì 24 ottobre 2018
Ore 11:00, aula Seminari RM004, Dipartimento di Scienze di Base e Applicate per Ingegneria (SBAI), via A. Scarpa 16
incontri di Analisi MaTÈmatica allo SBAI
Marco Degiovanni (Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia)
Multiple solutions of quasilinear equations with natural growth conditions and related problems
We prove the existence of multiple solutions for a class of quasilinear equations satisfying natural growth conditions. Degree theory techniques are applied. We also show that the class of quasilinear equations satisfying natural growth conditions, in a suitable enlarged sense, includes other families of equations apparently of different kind.


Mercoledì 24 ottobre 2018
Ore 12:15, aula Seminari RM004, Dipartimento di Scienze di Base e Applicate per Ingegneria (SBAI), via A. Scarpa 16
incontri di Analisi MaTÈmatica allo SBAI
Manuel Gnann (Technical University of Munich, Germany)
Analysis of moving contact line motion
We consider a lubrication approximation of the Navier-Stokes equations, known as thin-film equation, modeling the motion of a three-dimensional viscous thin fluid film. We are specifically interested in the movement of the contact line, that is, the triple junction separating the three phases liquid, gas, and solid. The understanding of the singular behavior of solutions at the contact line is of physical interest since it is linked to different physical assumptions at the triple junction and at the liquid-solid interface. Mathematically this leads to the question regarding regularity of a degenerate-parabolic fourth-order free boundary problem, for which a comparison principle is violated. By deriving suitable estimates in weighted Sobolev spaces, we are able to prove existence and uniqueness of solutions and to characterize the contact-line singularity to leading orders.


Mercoledì 24 ottobre 2018
Ore 14:00, aula L
seminario di Algebra e Geometria
Nicolas Bergeron (Sorbonne Université et Département de Mathématiques et Applications de l'ENS)
On the cohomology ring of the universal K3 surface
The Deligne decomposition theorem reduces the study of the cohomology groups of the universal K3 surface, or more generally of universal families of polarized hyperkähler varieties, to the study of certain spaces of automorphic forms. This makes it possible to prove a cohomological version of the generalized Franchetta conjecture due to O'Grady but also to better understand the ring structure on the cohomology of these universal families. This is a joint work with Zhiyuan Li.


Mercoledì 24 ottobre 2018
Ore 14:30, aula Dal Passo, dipartimento di Matematica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1
seminario di Geometria Algebrica
Mikhail Zaidenberg (Institut Fourier, Grenoble, FRANCE)
Fano-Mukai fourfolds of genus 10 and their automorphism groups
The seminar is in the framework of Research project "Families of curves: their moduli and their related varieties" - Mission Suistanability Tor Vergata, CUP: E81|18000100005, PI Flaminio Flamini. The celebrated Hirzebruch Problem asks to describe all possible smooth compactifications of C^n with second Betti number 1. Projective completions of C^n are Fano varieties; in dimension at most 3 they are all known (Remmert-van de Ven, Brenton-Morrow, Peternell, Prokhorov, Furushima). It occurs that any variety in the title provides a new example in dimension 4. These varieties form a 1-parameter family. The group Aut^0(V) of a general member V of this family is isomorphic to the algebraic 2-torus (C^*)^2. There are two exceptional members of the family with Aut^0(V) equal GL(2, C) and C x C^*, respectively. The discrete part of the automorphism group Aut(V) is a finite cyclic group. To compute Aut(V) we use three different geometric realizations of Aut(V). The talk is based on a joint work with Yuri Prokhorov


Mercoledì 24 ottobre 2018
Ore 15:00, aula 311, Pal. C, Dipartimento di Matematica e Fisica, Università di Roma Tre, largo san Leonardo Murialdo 1
seminario di Analisi Matematica
Professoressa Roberta Musina (Università di Udine)
Sobolev inequalities for fractional Neumann Laplacians on half spaces
We consider different fractional Neumann Laplacians of order s, 0‹s‹1 on half spaces, namely, the Restricted Neumann Laplacian, the Semirestricted Neumann Laplacian and the Spectral Neumann Laplacian. In particular, we are interested in the attainability of the Sobolev constants for these operators. This is joint work with Alexander I. Nazarov (St. Petersburg Department of Steklov Institute and St. Petersburg State University, Russia).


Mercoledì 24 ottobre 2018
Ore 16:00, aula 211 - Pal. C, Dipartimento di Matematica e Fisica, Università di Roma Tre, largo san Leonardo Murialdo 1
seminario di Probabilità
Ivailo Hartarsky (ENS, France)
Bootstrap percolation : subcritical universality class and oriented percolation
Bootstrap percolation is a wide class of deterministic monotone cellular automata with random initial state closely related to several other statistical physics models such as the kinetically constrained spin models for the spin glass transition. There are three 'universality classes' of bootstrap percolation in two dimensions. Of them the 'subcritical' ones those exhibiting a non-trivial phase transition are by far the most poorly understood. In this work we develop a first approach for studying them. We will start with a gentle introduction to the field and its universality picture to provide the necessary background. We will then introduce the main new notion of critical density and state our main result. We will then illustrate the method by applications to concrete examples yielding new and old results in the area. The approach establishes and exploits a tight connection with a new generalization of classical oriented percolation, whose further study will have a direct impact on bootstrap percolation. The talk will be based on the preprint arxiv:1806.11405.


Mercoledì 24 ottobre 2018
Ore 17:30, aula di Consiglio
seminario di Fisica Matematica
Soeren Fournais (Aarhus Universitet)
A simple 2nd order lower bound to the energy of dilute Bose gases



Tutte le informazioni relative a questo notiziario devono pervenire esclusivamente all'indirizzo di posta elettronica seminari@mat.uniroma1.it entro le ore 24 del giovedì precedente la settimana interessata. Le comunicazioni pervenute in ritardo saranno ignorate. Le informazioni devono essere inviate esclusivamente in formato testo: in particolare saranno ignorati link, allegati e codice TeX/LaTeX.
Tutti coloro che desiderano ricevere questo notiziario via e-mail sono invitati a comunicare il proprio indirizzo di posta elettronica a seminari@mat.uniroma1.it.

        Il Direttore

© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma