Notiziario Scientifico
Settimana dal 13 al 19 aprile 2015
Lunedì 13 aprile 2015
Lunedì 13 aprile 2015
Lunedì 13 aprile 2015
Martedì 14 aprile 2015
Martedì 14 aprile 2015
Martedì 14 aprile 2015
Martedì 14 aprile 2015
Mercoledì 15 aprile 2015
Mercoledì 15 aprile 2015
Mercoledì 15 aprile 2015
Mercoledì 15 aprile 2015
Mercoledì 15 aprile 2015
Mercoledì 15 aprile 2015
Giovedì 16 aprile 2015
Venerdì 17 aprile 2015
Venerdì 17 aprile 2015
Venerdì 17 aprile 2015
Tutte le informazioni relative a questo notiziario devono pervenire
all'indirizzo di posta elettronica
seminari@mat.uniroma1.it
entro le ore 9 del venerdì precedente la settimana di pubblicazione.
Ore 14:30, aula di Consiglio
Seminario di Analisi Matematica
We consider vectorial variational problems of the form E[u]=∫W(Du)dx,
typical for example of nonlinear elasticity and plasticity, which
include constraints on the determinant. Specifically, the energy density
W is assumed to diverge outside of the set of matrices with positive
determinant, or, alternatively, outside of the set of matrices with
determinant equal 1. If W is not quasiconvex then E is not lower
semicontinuous and does not, in general, have minimizers. Low-energy
states can be studied via the relaxation of E. We discuss how, in some
situations of physical interest, the relaxation of E can be explicitly
characterized in terms of the quasiconvex envelope of W. This talk is
based on joint work with Georg Dolzmann (Regensburg).
Ore 15:00, aula G, Università di Roma Tre (via della Vasca Navale)
Seminario di Fisica Teorica
It will be shown how the singularity structure shapes the evolution of
birational discrete systems, suggesting changes of variables which
automatically provide us with exact evaluation of the algebraic
entropy, (generalised) Hirota type of description, and remarkable
factorisation properties beyond "Laurentness".
Ore 16:00, IISS C. Darwin (via Tuscolana 388)
In occasione del primo anniversario della morte di Emma Castelnuovo,
il Movimento di Cooperazione Educativa e l'IISS C. Darwin aprono
"simbolicamente" la sua Biblioteca. Interviene Ciro Ciliberto
Ore 14:00, aula Riunioni (II piano), IAC (via dei Taurini)
Seminario di Probabilità
Our aim is to study quantitative central limit theorems for some
linear and nonlinear statistics based on wavelet coefficients evaluated on
spherical Poisson processes of arbitrary dimension. This purpose is
attained by merging the Stein-Malliavin approach (introduced in the
seminal paper by Peccati, Solé, Taqqu and Utzet (2010)) and the
properties of the needlets, wavelets over the q-dimensional sphere
featuring strong concentration properties in the spatial and frequency
domains, introduced in literature by Narcowich, Petrushev, Ward (2006).
We will also discuss some examples: the thresholding and the study
of variance in nonparametric density estimation framework and the so-
called Sobolev tests for uniformity.
This is a joint work with Solesne Bourguin, Domenico Marinucci and
Giovanni Peccati.
Ore 14:30, aula Dal Passo, Università di Roma Tor Vergata
Seminario di Equazioni Differenziali
Verranno presentati alcuni nuovi risultati riguardanti la dipendenza da p degli autovalori
variazionali del p-laplaciano. La questione verrà collegata alla Gamma-convergenza di
opportuni funzionali, mostrando in particolare che il comportamento del primo autovalore
condiziona quello di tutti gli autovalori variazionali successivi.
Ore 15:00, aula di Consiglio
Seminario di Modellistica Differenziale Numerica
Some recent developments of reduced order modelling (ROM) in computational fluid
dynamics for viscous incompressible flows will be discussed. The main topics will
deal with the use of combined ROM techniques currently available, efficient sampling
procedures, inf-sup pressure stabilization for ROM approaches, error bounds, computational
performances. Spectral elements method is used for basis generation. Some emphasis will
be given to the stability of flows and steady and Hopf bifurcations and numerical techniques
for their detections by the eigenvalues computed with reduced order models. Numerical
results will be applied to classical benchmarks study cases and to the Coanda effect
in cardiac blood flow simulation, provided as guideline and perspective application.
Ore 16:00, aula D'Antoni, Università di Roma Tor Vergata
Seminario di Analisi Complessa
We study a problem of separation of boundary singularities for generators of
continuous semigroups of holomorphic self-mappings. It enables us to recover
the famous Cowen-Pommerenke inequalities as well as to establish some quantitative
algebraic and geometric characteristics related to the linearization models for
semigroups of holomorphic mappings and the geometry of backward flow invariant domains.
Yet another look at the problem in question leads to an infinitesimal version of
boundary interpolation theorem for holomorphic generators in the spirit of Pick
and Nevanlinna. This talk is based on the joint works with Mark Elin, Simeon Reich,
Nikolay Tarkhanov and Larry Zalcman.
Ore 14:00, aula 1B1, Dipartimento SBAI
Minicorso
Ore 14:30, aula di Consiglio
Seminario di Algebra e Geometria
Negli anni Ottanta Mukai dimostra che le singolarità dello spazio dei moduli di fasci
su una superficie K3 sono contenute nel luogo dei fasci strettamente semistabili.
Se la polarizzazione rispetto a cui si considera la stabilità è generica e il vettore
di Mukai è primitivo tutti i fasci semistabili sono stabili e lo spazio dei moduli
è liscio e ha una struttura simplettica. Nel caso in cui il vettore di Mukai è
non primitivo, Kaledin, Lehn e Sorger congetturano che la dg-algebra che controlla le
deformazioni di fasci su una K3 sia formale, che implicherebbe una completa
descrizione delle possibili singolarità dello spazio di moduli.
La congettura è stata dimostrata in alcuni casi da
Kaledin-Lehn e successivamente da Zhang. Le tecniche utilizzate sono simili e consistono
nell'analizzare i sollevamenti dei fasci sulla K3 alla famiglia twistor e poi applicare
il teorema di formalità in famiglie di Kaledin. In un lavoro in progress in collaborazione
con Manfred Lehn vogliamo completare la dimostrazione della congettura. Nel seminario
parlerò della nostra dimostrazione per un caso mancante e del tentativo di estendere
la nostra costruzione ad hoc a una dimostrazione generale.
Ore 15:00, aula D'Antoni, Università di Roma Tor Vergata
Seminario PASCAL (Probabilistic and Statistical Techniques for Cosmological Applications)
We will revisit the so-called Fourth moment theorem due to Nualart and
Peccati from the point of view of Markov operators and will point out
the generalizations that this approach brings. We will derive
consequences for Variance inequalities and the Gaussian product
conjecture.
Ore 16:00, aula C
Ore 16:00, aula F, Università di Roma Tre (largo s. Leonardo Murialdo)
i Tè di Matematica
Faremo una breve introduzione al problema del trasporto ottimo e
vedremo come si collega all'analisi in spazi metrici.
Ore 16:15, aula di Consiglio
Seminario di Fisica Matematica
I will review some recent attempts to clarify rigorously the transition from a
quantum to a classical behavior of a microscopic system as a consequence of its
interaction with a macroscopic quantum system. Perturbative and non-perturbative
analysis of solutions of the Schroedinger equation of a large system, in specific
asymptotic regimes, reveals that the evolution of various subsystems turns out to
be classical-like without invoking any state reduction resulting
from a measurement process.
Ore 14:00, aula di Consiglio
Seminario p(n) Problemi Differenziali Non Lineari
This talk is about the one-dimensional nonlinear Schrodinger equation with a combination
of cubic focusing and quintic defocusing nonlinearities, and an attractive delta-function
potential. All standing waves with a positive soliton profile can be determined explicitly
in terms of elementary functions, and I will show by a bifurcation and spectral analysis
that all these solutions are orbitally stable. A remarkable feature is a regime of
bistability, where two stable solitons coexist.
aula Libera, Universitagrave; di Roma Tre, (largo G.B. Marzi)
9:00 Opening S. Gabriele, P. Magrone, V. Varano
9:15 the Students Some Workshop Results
9:45 S. Adriaenssens, S. Gabriele, P. Magrone, V. Varano (Princeton Univ., Roma Tre Univ.)
Comparisons between geometrical and structural analysis of the Musmeci's Basento bridge
10:30 T. Iori, S. Poretti (Tor Vergata Univ.) The Language of Structures.
Musmeci's nameless form bridge
11:00 Coffee break
11:30 S. Converso (Roma Tre Univ.) Parametric Design and Shape OpFmizaFon:
doubly curved envelopes in wood for the new congress center of Rome
12:00 L. Teresi (Roma Tre Univ.) Stress-driven Architectures: learning from Plants
12:30 M. Pezzulla (La Sapienza Univ.) Morphing of Geometric Composites
Ore 12:00, aula Picone
Seminari MoMa
Graphene is a two-dimensional material with a unique set of properties,
many of which rely on its planar two-dimensional structure. In many
applications, graphene is supported on a substrate. Rather than a flatland,
supported graphene describes a landscape shaped by out-of-plane features
with different physical origins. Defects such as dislocations or grain
boundaries can relax through out-of-plane deformations. Gas trapped between
graphene and the substrate can elastically deform graphene, producing blisters
of various shapes and sizes. Lateral strain produced upon cooling after
graphene synthesis invariably results in linear and localized wrinkles.
Such wrinkles or bubbles locally modify the electronic properties and are
seen as defects. It has been also suggested that the strong coupling between
localized deformation and electronic structure could be harnessed in technology
by strain engineering. Here, I will describe our efforts to understand the
origin of elastic out-of-plane deformations in supported graphene, and to
devise strategies to control deformation patterns.
Ore 14:30, aula 311, Università di Roma Tre (largo s. Leonardo Murialdo)
Seminario di Probabilità
We consider the stochastic PDE
ut=uxx+up+ε W
with homogenous Dirichlet boundary conditions, where p>1,
ε >0 is a small fixed parameter and W stands for
space-time white noise. It is well known that the associated
deterministic PDE (i.e. ε=0 in the equation above) admits
exactly one asymptotically stable equilibrium and a countable family
of unstable equilibria with increasing energy. Furthermore, for
certain initial conditions it can be shown that the solution of the
deterministic PDE explodes in finite time. We show that, for p<5
and initial conditions in the domain of attraction of the
asymptotically stable equilibrium, the solution Xε
of the SPDE satisfies in the limit as ε tends to zero the
classical description of metastability featured in [1]: the averages
of Xε remain stable and close to the equilibrium up until
the explosion time which, when suitably rescaled, converges in
distribution to an exponential random variable. Furthermore, for
certain initial conditions in the domain of explosion (and any value
of p>1) we show the continuity of the explosion time as
ε tends to zero.
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