Notiziario Scientifico
Settimana dal 23 al 29 marzo 2015
Lunedì 23 marzo 2015
Martedì 24 marzo 2015
Martedì 24 marzo 2015
Martedì 24 marzo 2015
Martedì 24 marzo 2015
Martedì 24 marzo 2015
Martedì 24 marzo 2015
Martedì 24 marzo 2015
Mercoledì 25 marzo 2015
Mercoledì 25 marzo 2015
Mercoledì 25 marzo 2015
Mercoledì 25 marzo 2015
Giovedì 26 marzo 2015
Giovedì 26 marzo 2015
Giovedì 26 marzo 2015
Giovedì 26 marzo 2015
Giovedì 26 marzo 2015
Giovedì 26 marzo 2015
Venerdì 27 marzo 2015
Venerdì 27 marzo 2015
Venerdì 26 marzo 2015
Venerdì 27 marzo 2015
Venerdì 27 marzo 2015
Venerdì 28 marzo 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 discuss some recent results related to the homogeneous Dirichlet problem
for the infinity Laplace equation with constant source in a bounded domain.
We characterize the geometry of domains for which an overdetermined problem
admits a viscosity solution. An essential tool is a regularity result for
viscosity solutions in convex domains, obtained by the convex envelope method
introduced by Alvarez, Lasry and Lions. Based on some recent joint works with
Ilaria Fragalà (Politecnico di Milano).
Ore 10:30, aula riunioni (secondo piano), IAC-CNR (via dei Taurini 19)
Seminario di Matematica Applicata
The study of drug/device combinations for controlled drug release has gained
significant momentum in recent years and is responsible for considerable global
research budgets across academia and Industry. In this talk, I will discuss my
group's research in this area which includes modelling drug release from
polymer-coated and nanoporous drug delivery devices, coupling drug release with
tissue absorption, and parameter estimation methods. The mechanisms of drug
release typically include diffusion, dissolution and in some cases a
combination of both. Within the tissue, convection, diffusion and reaction
typically occur simultaneously. We adopt a three-pronged approach to tackle
these problems, making use of analytical, numerical and experimental techniques.
Ore 14:00, aula di Consiglio
In this talk we define invariants for classical knots, singular knots and
framed knots. These invariant are constructed by using the Yokonuma-Hecke
algebras in the Jones recipe.
Ore 14:00, aula B
Metodi matematici per le teorie cinetiche
Le numerose obiezioni sollevate, sin dagli inizi, contro la teoria Boltzmann
del gas rarefatto, diffusero dubbi sulla possibilità di derivare
matematicamente l'equazione dalle leggi di Newton. Solo nel 1974 Oscar Lanford
pose fine a tali controversie dimostrando, in particolare, che
l'irreversibilità del sistema macroscopico è deducibile da una dinamica
microscopica reversibile. In questo seminario enuncerò il celebre risultato
e illustrerò in qualche dettaglio la strategia della prova. Ne discuterò poi
i limiti e i relativi problemi tuttora aperti.
Ore 14:30, aula 211, Università di Roma Tre
Seminario di Geometria
The problem of determining an effective bound on the multiple which makes an
ample divisor D on a smooth variety X very ample is natural and many results
are known in characteristic zero. In this talk I will discuss this problem
on surfaces in positive characteristic, giving a complete solution in this
setting. Our strategy requires an ad hoc study of pathological surfaces, on
which Kodaira-type theorems can fail. A Fujita-type theorem and a vanishing
result for big and nef divisors on pathological surfaces will also be
discussed. This is a joint work with Gabriele Di Cerbo.
Ore 14:30, aula Dal Passo, Università di Roma Tor Vergata
Seminario di Equazioni Differenziali
We investigate the existence of ground states for the subcritical NLS energy on
metric graphs. In particular, we describe a sufficient condition for the
existence of ground states and a topological assumption that prevents
existence. In order to obtain the results, we introduce a new rearrangement
technique, adapted to the graph where it applies. Owing to such a technique,
the energy level of the rearranged function is improved byconveniently mixing
the symmetric and monotone rearrangement procedures.
Ore 14:30, aula 311, Università di Roma Tre
Seminario di Fisica Matematica
Edge reinforced random walk (ERRW) and vertex reinforced jump processes (VRJP)
are history dependent stochastic processes, where the particle tends to come
back more often on sites it has already visited in the past. For a particular
scheme of reinforcement these processes are random walks in random environment
(mixing of reversible Markov chains) whose mixing measure can be related to a
non-linear sigma model introduced in the context of random matrix models for
quantum diffusion. I will give an overview on these models and explain some
recent results.
Ore 15:00, aula di Consiglio
Seminario di Modellistica Differenziale Numerica
We consider the numerical approximation of retarded potentials arising in wave
scattering problems. For the temporal approximation we consider a
generalization of Lubich's Convolution Quadrature which allows for variable
steps. The algorithmic realization of the new method relies on contour integral
techniques in the complex plane. Numerical experiments are provided to show the
potential of our approach.
Ore 14:00, aula G
We consider a nearest-neighbor random walk on Z whose probability w(x,n) to
jump to the right from site x depends not only on x but also on the number of
prior visits n to x. The collection (w(x, n)) is sometimes called the "cookie
environment" due to the following informal interpretation. Upon each visit to
a site the walker eats a cookie from the cookie stack at that site and chooses
the probability to jump to the right according to the "flavour" of the cookie
eaten.Assume that the cookie stacks are i.i.d. and that only the first M
cookies in each stack may have "flavour". All other cookies are assumed to be
"plain", i.e. after their consumption the walker makes unbiased steps to one
of its neighbours. The "flavours" of the first M cookies within the stack can
be different and dependent. We discuss recurrence/transience, ballisticity,
and limit theorems for such walks. The talk is based on joint works with
Dolgopyat (University of Mary-land), Mountford, Zerner.
Seminario di Algebra e Geometria
Ore 14:30, aula di Consiglio
Models (simplicial, cellular...) of topological spaces are usually equipped
with various operations: products, dualities, cohomological operations, and
so on. One can also consider topological spaces from another point of view:
instead of looking at the internal structure of each space, one can consider
their collective structure. In the particular case of finite spaces, they are
in bijection with quasi-orders, and it is natural to investigate their linear
span using techniques of algebraic combinatorics. New operations and structure
theorems arise from this point of view, as well as connexions with Hopf
algebras such as the one of quasi-symmetric functions. Joint work with L.
Foissy and C. Malvenuto.
Ore 14:30, aula Dal Passo, Università di Roma Tor Vergata
Investigation of the energy transport in crystals is one of the main problems
in the non-equilibrium statistical mechanics. Since it turns out to be
extremely difficult, usually one studies toy models, possessing additional
ergodic properties. A common idea is to consider a Hamiltonian system of
particles where each mode is a subject to stochastic perturbation. Clearly,
it is important to study the case when the perturbation goes to zero.
In this talk I will discuss dynamics of a system of weakly interacting
oscillators, where each oscillator is weakly coupled with its own stochastic
Langevin thermostat. The system can be interpreted as a crystal plugged in
medium and weakly interacting with it. I will prove that, under the limit when
the couplings of oscillators with each other and with the thermostats go to
zero with some precise scaling, behavior of the system is governed by an
effective equation which is a rather nice dissipative SDE. I will show that
under the limit above, dynamics of the energy satisfies laws, which resemble
the Fourier law and the Green-Kubo formula (but which are not the F. law and
the G.-K. formula).
Ore 15:00, aula Picone
Interventi introduttivi:
Emanuele Caglioti (Direttore del Dipartimento di Matematica G. Castelnuovo)
Corrado Mascia (Referente per lo Sportello Matematico)
Come nasce lo Sportello Matematico, Roberto Natalini (Direttore IAC-CNR e
Co-fondatore dello Sportello Matematico)
Come funziona lo Sportello Matematico, Antonino Sgalambro (IAC-CNR e
Coordinatore dello Sportello Matematico)
Esperienze di successo: il caso CrestOptics,
Vincenzo Ricco (Presidente CrestOptics srl)
Raino Ceccarelli (CrestOptics srl)
Vittoria Bruni (Dipartimento SBAI Sapienza e IAC-CNR)
Il ruolo del Traduttore Tecnologico, Maurizio Ceseri e Anna Melchiori
(Team dello Sportello Matematico)
Dibattito
Seminario P(n): problemi differenziali non lineari
Ore 14:00, aula di Consiglio
Seminari Formulas
Ore 14:30, aula Zorzi, Università di Roma Tre
Dopo un brevissimo sommario sui numeri costruibili con riga e compasso,
tratteremo in qualche dettaglio i numeri costruibili tramite origami. Un
numero, (algebrico totalmente reale) si dice costruibile per origami se è
possibile ottenerlo come lunghezza di un segmento ottenuto attraverso
piegamenti (ammissibili) dal segmento unitario. Faremo vedere esplicitamente
come costruire la radice cubica di 2 (o di qualsiasi altro numero intero),
attraverso il quadrato di Beloch.
Seminario di Geometria
Ore 14:45, aula 211, Università di Roma Tre
A conjecture of Yau, Tian and Donaldson is that the existence of a canonical
Kahler metric on an ample line bundle L over projective variety X should be
equivalent to K-stability, an algebro-geometric notion which is closely related
to Geometry Invariant Theory. However, K-stability is understood in very few
specific cases. Given a K-stable Fano variety X, we show that certain finite
covers of X are also K-stable, giving algebro-geometric proofs of K-stability
in several new examples.
Seminario di Geometria
Ore 15:00, aula 1B1, dipartimento SBAI
Workshop Proofs and Types, 25 years later
aula Verra, Università di Roma Tre
15:30 Wagner de Campos Sanz (Universidade de Goia's) TBA
16:15 Giulio Guerrieri (Université Paris VII) Injectivity of relational
semantics for connected MELL proof-structures via Taylor expansion
17:15 Jean Fichot (IHPST, Université Paris I) May Falsum be true?
Seminario di Geometria
Ore 16:00, aula 211, Università di Roma Tre
In this talk I will showcase a general class of smooth rational cubic fourfolds
X containing a plane whose associated quadric surface bundle does not have a
rational section. Equivalently, the Brauer class B of the even Clifford algebra
over the discriminant cover (a K3 surface S of degree 2) associated to the
quadric bundle, is nontrivial. These fourfolds provide nontrivial examples
verifying Kuznetsov's conjecture on the rationality of cubic fourfolds
containing a plane. I will then explore the connections between this
construction and the existence of one-apparent-double-point surfaces inside
the cubic 4fold.
Workshop Proofs and Types, 25 years later
aula Verra, Università di Roma Tre
09:00 Jean-Yves Girard (Université Aix-Marseille) La suprenante syntaxe
transcendantale du calcul des predicats
15:30 Pierre-Louis Curien (Université Paris VII) Curry-Howard correspondence,
abstract machines, sequent calculus, and classical logic
16:15 Jean-Baptiste Joinet (Université Lyon 3) On the primitive distinction
Individual/Predicate
17:15 Pierre Livet (Université Aix-Marseille) Epistemic circularity:
self-justification versus self-application; meaning as the source of
use or computational functioning as the regulation of impredicativity?
Seminario di Logica e Geometria della Cognizione
Ore 11:30, aula 311, Università di Roma Tre
Saranno esaminate alcune forme di "circolarità" che appaiono nella teoria
della dimostrazione della logica del secondo ordine e della sua controparte
costruttiva, il Sistema F. Queste circolarità, o "circoli viziosi"
(Poincaré 1906), saranno analizzate sulla base della distinzione tra due
punti di vista corrispondenti a metodologie distinte e irriducibili (a causa
dei teoremi di incompletezza): il primo ("le pourquoi", Girard 2000) è
focalizzato sulla questione della coerenza e dell'Hauptsatz e richiede dei
metodi di dimostrazione infinitari (ovvero non elementari). Il secondo ("le
comment", Girard 2000) è focalizzato sul contenuto computazionale e
combinatorio delle dimostrazioni, dato dalla corrispondenza tra prove e
programmi, e non richiede che metodi elementari di dimostrazione. Questa
distinzione metodologica permette di mettere in luce nel dettaglio le
limitazioni epistemologiche cui va incontro la logica del secondo ordine:
cosa può essere deciso in modo elementare, ovvero con certezza? cosa invece
non può mai essere stabilito al di la' di ogni ragionevole dubbio?
Seminari MoMa
Ore 12:00, aula di Consiglio
The problem of an elastic rod deforming in a plane, namely the so-called
"planar elastica", has a long history, rooting to Jacob Bernoulli (1654-1705),
Daniel Bernoulli (1700-1782), Leonhard Euler (1707-1783), and Pieter van
Musschenbroek (1692-1761), but is still actual and rich of applications,
sometimes unexpected. The elastica has attracted a great interest in the past
and has involved contributions from first-class scientists, including
Kirchhoff, Love, and Born. The research on the elastica marked the initiation
of the calculus of variations and promoted the development of the theory of
elliptic functions. Nowadays the elastica represents a useful introduction to
the theory of nonlinear bifurcation and stability, but is also an important
tool in the field of soft robotics and in the design of compliant mechanisms.
Moreover, the elastica can be effectively used to explain snake or fish
locomotion and to design snake-like robots.
In this talk, the theory of a planar, nonlinear elastic rod developed by Euler
is used to present new phenomena in which nonlinearities (related to the fact
that equilibrium of the rod is reached at large displacements) play a
fundamental role.
Ore 14:00, aula B
Metodi matematici per le teorie cinetiche
Nel seminario sarà discussa l'applicazione della tecnica dell’espansione di
Hilbert al limite idrodinamico, per tempi piccoli, dell'equazione di Boltzmann
verso l'equazione di Eulero. L'approccio iniziale consisterà nello scrivere
la serie formale nel parametro perturbativo e, risolvendo ricorsivamente
equazioni lineari, si ricostruirà la struttura dei termini di ordine più
basso. Lo studio di particolari proprietà dell'operatore di collisione
linearizzato permetterà di giustificare l'approccio iniziale.
Ore 15:00, aula INdAM
Seminario Control, Dynamics & PDEs
The connection mentioned in the title is well-known (see, for example, A.S.
Sznitman, Brownian motion in a Poissonian potential, 1993, PTRF). The goal of
the talk is to review some necessary facts from large deviations theory and
explain that this connection is actually an equivalence.
Workshop Proofs and Types, 25 years later
aula Verra, Università di Roma Tre
09:30 Alain Lecomte (Université Paris VIII) Ludics and philosophy of language:
from literal meaning to dialogue modeling
10:30 Marco Pedicini (Università Roma Tre) Sequential and parallel abstract
machines for optimal reduction
11:15 Vito Michele Abrusci (Università Roma Tre) Logic, first-order logic,
second-order logic in Hilbert's logical school (1920-1940): some
historical remarks.
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