Notiziario Scientifico
Notiziario dei Seminari di carattere matematico
a cura del Dipartimento 'G. Castelnuovo'
Sapienza Università di Roma
Settimana dal 23 al 29 novembre 2015
Lunedì 23 novembre 2015
Ore 11:00, aula B
Incontro di lavoro su Calcolo delle Variazioni e Γ-convergenza/
Working seminar on Calculus of Variations and Γ-convergence
Roberto Alessi (Sapienza Università di Roma)
Energetic formulation for rate-independent processes:
remarks on discontinuous evolutions with a simple example
Lunedì 23 novembre 2015
Ore 14:30, aula di Consiglio
Seminario di Analisi Matematica
Marco Degiovanni (Università Cattolica del Sacro Cuore)
Grado topologico ed equazioni quasilineari con secondo membro misura
Si considera un'equazione quasilineare con secondo membro misura il cui primo
membro non definisce un operatore coercivo. Si dimostra un risultato di esistenza
del tipo alternativa di Fredholm. per questo scopo viene introdotta una variante
di grado topologico adatta a tale contesto.
Martedì 24 novembre 2015
Ore 14:30, aula Dal Passo, Università di Roma Tor Vergata
Seminario di Equazioni Differenziali
Luca Fanelli (Sapienza Università di Roma)
About the Uncertainty Principle
The Uncertainty Principle establishes a bound from below for the product of
conjugated physical observables. There are many mathematical evidences of this
fact, including variational inequalities between potential and kinetic energies,
rigidity theorems in Fourier Analysis and unique continuation prioperties in
PDEs. We will introduce a connection between the above different topics, finally
focusing our attention on unique continuation properties and gaussian decay
of Schrödinger evolutions.
Martedì 24 novembre 2015
Ore 15:00, aula di Consiglio
Seminario di Modellistica Numerica Differenziale
R. Smits (New Mexico State University)
Some theoretical results about the normalized p-Laplacian based on its numerical analysis
A numerical scheme developed by Falcone, Finzi Vita, Giorgi and myself will be discussed
for approximating the p-Laplacian based on a 2-player game called tug-of-war with noise.
Consequential numerical results will be shown which have inspired a sequence of theoretical
results. I will discuss theoretical results obtained with my
collaborators including a mean value property for p-harmonic functions, a
concrete realization of Wolff's example used in the proof that p-harmonic
measure is not additive and discuss the local behavior of the Poisson
problem for the game p-Laplacian in a corner.
Time permitting I will discuss some current work on the 4-Laplacian in 2
dimensions which appears to have a remarkably simple numerical scheme.
Martedì 24 novembre 2015
Ore 15:30, aula Dal Passo, Università di Roma Tor Vergata
Seminario di Geometria Algebrica
Thomas Dedieu
Dimostrazione della formula di Caporaso-Harris: geometria delle varietà di Severi
Martedì 24 novembre 2015
Ore 16:00, aula G
Seminario per insegnanti (Piano Lauree Scientifiche)
Paolo Maroscia (Sapienza Università di Roma)
L'umorismo: una risorsa preziosa per l'insegnamento della matematica
Lunedì 25 novembre 2015
Ore 14:30, aula di Consiglio
Seminario di Geometria ed Algebra
Gavril Farkas (Berlin Humboldt)
Compact moduli of Abelian differentials
The moduli space of holomorphic differentials (with prescribed zeros and poles) on
nonsingular curves is not compact since the curve may degenerate. I will discuss
a compactification of these strata in the moduli space of Deligne-Mumford stable
pointed curves, which includes the space of canonical divisors as an open subset.
The theory leads to geometric/combinatorial constraints on the closures of the
strata of holomorphic differentials and as a consequence, one can determine the
cohomology classes of the strata. This is joint work with Rahul Pandharipande.
Mercoledì 25 novembre 2015
Ore 16:00, aula di Consiglio
Seminario di Fisica Matematica
Umberto Montemagno (Sapienza Università di Roma)
Synchronization and dephasing results for Kuramoto model
The seminar is about the Kuramoto model, a deterministic model that
describes a large population of coupled oscillators with natural
frequencies drawn from some prescribed distribution. I will present
the results obtained in collaboration with Dario Benedetto and Emanuele
Caglioti about synchronization and dephasing. In particular it will be
shown that, in the case of identical oscillators, the phase-synchronization
is the 'typical' behavior. In the small coupling regime, it will be proved
the dephasing of the oscillators by using the decaying of the order parameter.
The techniques used in this second part take inspiration from the literature
on the Landau Damping.
Mercoledì 25 novembre 2015
Ore 16:00, aula F, Università di Roma Tre, largo san L. Murialdo 1
Colloquium di Matematica
Kenneth M. Golden (University of Utah)
Modeling the Melt: What Math Tells Us About the Disappearing Polar Ice Caps
The precipitous loss of Arctic sea ice has far outpaced expert
predictions. In this lecture we will explore the mathematical
underpinnings of this mystery, and show how we are using the
mathematics of multiscale composites, statistical physics, and
dynamical systems to study key sea ice processes. This work is helping
to better represent sea ice in climate models, and improve projections
of the fate of Earth's ice packs and the response of polar
ecosystems. We will conclude with a short video from a 2012 Antarctic
expedition where sea ice properties were measured.
Giovedì 26 novembre 2015
Ore 14.00, aula 211, Università di Roma Tre,
largo san L. Murialdo 1
Seminario di Geometria
Yoav Len (Saarland University)
Counting curves with fixed j-invariant
I will discuss a correspondence between the number of algebraic and
tropical elliptic curves on toric surfaces with fixed j-invariant.
The proof combines ideas from tropical geometry with recent tools from
log geometry. As an application, we obtain a new enumerative formula
for Hirzerbruch surfaces, relating the number of such curves with the
number of rational curves having mild tangency with the boundary.
In addition, I will show how the correspondence theorem is used to
recover Pandharipande's formula for the projective plane.
This is joint work with Dhruv Ranganathan.
Giovedì 26 novembre 2015
Ore 15.15, aula 211, Università di Roma Tre,
largo san L. Murialdo 1
Seminario di Geometria
Michael Hoff (Saarland University)
On osculating cones to Brill-Noether loci
Let C be a general canonical embedded curve of genus g and let W_d(C)
be the Brill-Noether locus. In an article from 1988, Kempf and Schreyer
studied the geometry of the osculating cone to the theta divisor W_{g-1}(C)
at a general singular point and showed that one can recover the curve C
from the osculating cone. We believe that similar results are true for
all W_d(C). In my talk, I will describe the osculating cone to W_d(C)
at a smooth isolated point of W^1_d(C) (hence an isolated singularity
of W_d(C)) for C of even genus g=2(d-1). In particular, I will show
that the curve C is a component of the osculating cone. The proof is
based on techniques introduced by Kempf in 1986. This is joint work
with Ulrike Mayer (Saarland University).
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 di pubblicazione.
Le comunicazioni pervenute in ritardo saranno ignorate.
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