Notiziario Scientifico

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

Settimana dal 15-02-2021 al 21-02-2021

Lunedì 15 febbraio 2021
Ore 11:30, Il seminario sarà tenuto in modalità telematica, Dipartimento di Matematica e Fisica, Università degli Studi RomaTre, Largo San Leonardo Murialdo 1
Seminario di Fisica Matematica
Sébastien Ott (Università degli Studi Roma Tre)
An alternative proof of the roughening transition in 2D SOS model
In this talk, I will present a soft proof of the roughening transition in the SOS model, providing an alternative approach to part of the famous Fröhlich and Spencer 1981 paper. I will focus on 0 boundary conditions and the square lattice and briefly mention extensions to other boundary conditions and graphs. Based on recent joint work with Piet Lammers.
SI NOTINO il giorno e l'ora inusuali !!! Per partecipare al Seminario cliccare sul seguente Link


Mercoledì 17 febbraio 2021
Ore 14:00, Seminario telematico via Google Meet all'URL http://meet.google.com/jjt-toji-skw, Dipartimento di Matematica, Sapienza Università di Roma
seminario di Algebra e Geometria
Mattias Jonsson (University of Michigan)
Filtrations on section rings and non-Archimedean geometry
To any polarized variety (X,L) is associated a section ring R. I will explain the relation between suitable classes of norms on R and functions on the Berkovich analytification of X. Time permitting, I will discuss applications of this to K-stability. This is joint work with S. Boucksom.
Per informazioni, rivolgersi a: diverio@mat.uniroma1.it


Mercoledì 17 febbraio 2021
Ore 14:30, teleconferenza, https://meet.google.com/pip-kvzt-fkz
Seminario delle Meccaniche
Stefano Lepri (CNR-ISC, Firenze)
Transport in perturbed integrable anharmonic chains
Nonequilibrium and thermal transport properties of classical integrable 1D systems like the Toda chain or the hard point gas, subject to additional (nonintegrable) terms are considered. For energy and momentum-conserving weak perturbations, heat transport is mostly supplied by quasiparticles with a very large mean free path l. Upon increasing the system size L, three different regimes can be observed: a ballistic one, an intermediate diffusive range, and, eventually, the crossover to the anomalous (hydrodynamic) regime. We discuss the case of the perturbed harmonic chain, which exhibits a yet different scenario.


Giovedì 18 febbraio 2021
Ore 14:00, Seminario online su questo link, Dipartimento di Matematica, Università di Roma "Tor Vergata"
Colloquium di dipartimento
Toshiyuki Kobayashi (The University of Tokyo)
A foundation of group-theoretic analysis on manifolds
Symmetry of geometry is inherited by symmetry of function spaces, called the regular representation. From this viewpoint, the classical theory of expansions such as Fourier series or spherical harmonics may be interpreted as "analysis and synthesis" of the regular representation. In this talk, we address the following fundamental questions about the regular representation on manifolds X acted algebraically by reductive Lie groups G such as GL(n,R). A.  Does the group G "control well"  the space of function on X? B.  What can we say about "spectrum" for \(L^2(X)\)?  We highlight "multiplicity" for A and "temperdness" for B, and explain some geometric ideas of the solution.
N.B.:  this talk is part of the activity of the MIUR Excellence Department Project CUP E83C18000100006.
Per informazioni, rivolgersi a: molle@mat.uniroma2.it


Giovedì 18 febbraio 2021
Ore 14:30, Canale Youtube di Cnr-IAC https://www.youtube.com/watch?v=5t9Y-zrXfH4, Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche
Seminari generali IAC 2021
Giovanni Franzina (Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche)
Diffusive models for EM signals in seismology
We model magnetic anomalies at Earth’s surface due to hypogene co-seismic sources with classic magneto-quasistatic Maxwell’s equations in heterogeneous media.
Per informazioni, rivolgersi a: roberto.natalini@cnr.it


Giovedì 18 febbraio 2021
Ore 14:30, Sala di Consiglio - https://meet.google.com/ads-dekx-bgm, Dipartimento di Matematica, Sapienza Università di Roma
Seminario P(n)
Luca Martinazzi (Università di Padova)
Entire solutions to a prescribed curvature equation in \(\mathbb R^4\)
Several existence and non-existence results for the Nirenberg problem of prescribing the Gauss curvature on a closed surface are classically known. In higher dimension, analog results hold with the Q-curvature replacing the Gauss curvature. In many cases a non-existence result is associated with a blow-up phenomenon which leads to entire solutions of the Liouville equation \(-\Delta u = e^{2u}\) in dimension 2 or higher-dimensional analogs. On the other hand, Borer, Galimberti and Struwe studied a blow-up phenomenon which could lead to solutions to the equation \(-\Delta u =(1-|x|^2)e^{2u}\) in \(\mathbb R^2\) (1) or \(\Delta^2 u =(1-|x|^2)e^{4u}\) in \(\mathbb R^4\) (2) While non-existence results have been shown for (1) by Struwe, the question remained opened for (2). We recently gave a positive answer with A. Hyder, giving sharp conditions under which (2) admits solutions with controlled behaviour at infinity, hence answering an open question by Struwe. More related open questions will be discussed.
Per informazioni, rivolgersi a: galise@mat.uniroma1.it


Venerdì 19 febbraio 2021
Ore 15:00, Il seminario sarà tenuto in modalità telematica, Dipartimento di Matematica e Fisica, Università degli Studi RomaTre, Largo San Leonardo Murialdo 1
Seminario di Logica e Informatica Teorica
Giulio Guerrieri (Università di Bath)
Categorifying Non-Idempotent Intersection Types
Non-idempotent intersection types can be seen as a syntactic presentation of a well-known denotational semantics for the lambda-calculus, the category of sets and relations. Building on previous work, we present a categorification of this line of thought in the framework of the bang calculus, an untyped version of Levy’s call-by-push-value. We define a bicategorical model for the bang calculus, whose syntactic counterpart is a suitable category of types. In the framework of distributors, we introduce intersection type distributors, a bicategorical proof relevant refinement of relational semantics. Finally, we prove that intersection type distributors characterize normalization at depth 0. This is joint work with Federico Olimpieri, accepted at CSL 2021.
Per partecipare al Seminario cliccare sul seguente Link


Venerdì 19 febbraio 2021
Ore 16:00, Il seminario sarà tenuto in modalità telematica, Link per partecipare: https://uniroma1.zoom.us/meeting/register/tZwtcOGqqzkpE9yen93NMtuUttv031ZmB9lt
Seminari per insegnanti (PLS)
Luca Lorenzetti (Università della Tuscia)
Lingue, parole e numeri: fenomeni linguistici calcolabili e non calcolabili


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