Notiziario Scientifico
Notiziario dei Seminari di carattere matematico
a cura del Dipartimento 'G. Castelnuovo'
Sapienza Università di Roma
Settimana dal 22 al 28 giugno 2015
Lunedì 22 giugno 2015
Lunedì 22 giugno 2015
Lunedì 22 giugno 2015
Martedì 23 giugno 2015
Martedì 23 giugno 2015
Martedì 23 giugno 2015
Mercoledì 17 giugno 2015
Mercoledì 24 giugno 2015
Mercoledì 24 giugno 2015
Giovedì 25 giugno 2015
Giovedì 25 giugno 2015
Venerdì 26 giugno 2015
Venerdì 26 giugno 2015
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.
Ore 11:00, aula F, Università di Roma Tre
(largo san L. Murialdo)
Colloquium of Rome graduate students
The aim of this talk is to understand whether and how the critical
properties of an homogeneous model are modified by the addition of a
disorder. To be more concrete we consider a random walk and we allow
interactions between the random walk and its states. This interaction
depends on an external disorder which perturbs the random walk
behavior. According to the interactions choice, we have different kind
of models - like the pinning model or the directed polymer in random
environment. Our purpose is to describe some of them and present some
new and known results.
Ore 12:00, aula F, Università di Roma Tre
(largo san L. Murialdo)
Colloquium of Rome graduate students
The concept of P-kernel for a partially ordered set P was
introduced in the ninetieth by Richard Stanley, in order to abstract the
characteristics of some combinatorial objects which appear in different
contexts. Two classical examples appear in Ehrhart theory (integer lattice
points of a polytope) and in Kazhdan-Lusztig theory (representations of
Coxeter groups and their Hecke algebras). In this talk I'll try to explain
part of the general theory and I'll give new examples of P-kernels.
Ore 14:30, aula di Consiglio
Seminario di Equazioni Differenziali
We study the existence of cylindrically symmetric electro-magneto-static
solitary waves for a system of a nonlinear Klein-Gordon equation coupled
with Maxwell's equations in presence of a positive mass and of a
nonnegative nonlinear potential. Nonexistence results are provided
as well.
Ore 14:30, aula Dal Passo, Università di Roma Tor Vergata
Seminario di Equazioni Differenziali
In this talk we will study the problem of prescribing Gaussian curvature
on compact surfaces under conformal change of the metric with conical
singularities. We restrict our attention to the case of the unit sphere
and the case of sign-changing prescribed function, which presents some
extra difficulties. Joint work with F. de Marchis
(Sapienza università di Roma).
Ore 15:00, aula 311, Università di Roma Tre
(largo san L. Murialdo)
Seminario di Analisi
Ore 15:00, aula C, Università di Roma Tre
(via della Vasca Navale)
Colloqui di Fisica
Although it was discovered more than a century ago, superconductivity
(SC) still keeps its charm and is one of the most actively
investigated subjects in condensed-matter physics. Our understanding
of SC rests on two milestone paradigms: the Landau theory of normal
Fermi liquids and the Bardeen-Cooper-Schrieffer (BCS) theory of SC.
The former describes the metallic state where sizably interacting
electrons give eventually rise to weakly interacting
'quasiparticles'. According to the BCS theory, these nearly free
quasiparticles are then paired by the attractive forces mediated by
the phonons, thereby forming singlet pairs with opposite momentum. As
soon as they are formed, these electron pairs condense in a coherent
macroscopic quantum state giving rise to the superconducting phase. In
the last three decades, both these 'classical' paradigms have been
challenged and an increasingly long list of materials has been found,
where the metallic phase seems not to be a Fermi liquid and SC emerges
in some anomalous way. One quite common feature of these anomalous
superconducting systems is that the concept of quantum criticality is
somehow involved in their strange physical properties. This talk aims
to briefly revise the above traditional concepts to contrast the
anomalous metallic and superconducting behaviors of these new
materials, which are described emphasizing their intriguing proximity
to quantum criticality.
Ore 14:30, aula di Consiglio
Seminario di Algebra e Geometria
Together with any supergroup, one can naturally associate the pair made of its
classical (i.e. non super) underlying group and its tangent Lie superalgebra,
two objects which obey some obvious mutual compatibility constraints; any similar
pair is called 'super Harish-Chandra pair' (=sHCp). This construction leading from
supergroups to sHCp's is functorial, and actually an equivalence, as an explicit
quasi-inverse functor is known.
In this talk I present a new, totally different recipe for such a quasi-inverse:
indeed, it extends to a much larger setup, with a more geometrical method.
I shall mainly adopt the point of view of algebraic (super)geometry, but the bunch
of ideas and results we shall be dealing with actually applies to the real
differential, the real analytic and the complex analytic case as well.
Ore 14:30, aula Picone
Seminario congiunto di Probabilità (Roma 1 e Roma 3)
In 1998 the physicists Hastings and Levitov introduced a family of
continuum models to describe a range of physical phenomena of planar
aggregation/diffusion. These consist of growing random clusters on
the complex plane, which are built by iterated composition of random
conformal maps. It was shown by Norris and Turner (2012) that in the
case of i.i.d. maps the limiting shape of these clusters is a disc:
in this talk I will show that the fluctuations around this shape are
given by a random holomorphic Gaussian field F on {|z| > 1},
of which I will provide an explicit construction. When the cluster
is allowed to grow indefinitely, I will show that the boundary
values of F converge to a distribution-valued Fractional Gaussian
Field on the unit circle, which is log-correlated, and critical
in a sense that I will explain.
Ore 15:30, aula Picone
Seminario congiunto di Probabilità (Roma 1 e Roma 3)
The East model is a one-dimensional interacting particle system
with non attractive spin-flip dynamics. In the physics literature,
it is a key example of a model with glassy features. Here we take
this model as a random environment and investigate the behaviour
of a random walk whose jump rates depend on the current configuration.
The analysis relies on general results established for random walks
in random environment when the environment is Markovian with positive
spectral gap.
Ore 11:00, aula 34, Dipartimento di Scienze Statistiche
Ore 14:00, aula di Consiglio
14.00 E.N. Dancer
15.00 F. Gladiali
16.10 D. Bonheure
17.15 D. Hauer
Ore 09:00, aula di Consiglio
09.00 E.M. dos Santos
10.00 W. Reichel
11.15 Y. Sire
12.15 R. Musina
Ore 14:30, Dipartimento di Matematica, Università di Roma Tor Vergata
The following mathematicians have acceted to deliver a talk:
Xavier Cabré (UPC Barcelona),
Maria J. Esteban (Paris Dauphine),
Michael Struwe (ETH Zurich),
Claude Viterbo (ENS Paris).
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