Notiziario Scientifico
Settimana dal 27 aprile al 3 maggio 2015
Lunedì 27 aprile 2015
Martedì 28 aprile 2015
Mercoledì 29 aprile 2015
Giovedì 30 aprile 2015
Giovedì 30 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
The well-studied power-law-nonlinearity elliptic PDE is known to exhibit
a variety of interesting effects, including non-existence, non-uniqueness
and concentration phenomena. The application of formal-asymptotic and
symmetry methods in characterising such behaviour in terms of the domain
geometry will be illustrated, focussing on the infinite strip. Implications
for 'fast' nonlinear diffusion will be noted.
Ore 15:00, aula di Consiglio
Seminario di Modellistica Differenziale Numerica
Front propagation is an ubiquitous feature of reactive phenomena, in
particular in the dynamics of excitable media. Standard mathematical
counterparts are traveling-waves for reaction-diffusion equations,
starting from the Fisher-KPP and the Allen-Cahn equations. These are
both of parabolic nature as consequence of a modeling of the diffusion
process based on the Fick's law.
In this talk, I will discuss models where the diffusion is described
by means of a velocity-jump process, leading to a reaction-diffusion
equation of hyperbolic type. A basic example, determined by the choice
of two possible opposite velocities with equal probability of speed
reversal, is called Allen-Cahn equation with relaxation. Results
relative to this case, obtained in collaboration with C. Lattanzio
(L'Aquila, Italy), R. Plaza (UNAM, Mexico), C. Simeoni (Nice, France),
will be presented with emphasis on the numerical exploration of the
model. Then, the intention is to discuss possible future research
directions for the case of an arbitrary, but finite, number of speeds.
Ore 14:30, aula di Consiglio
Seminario di Algebra e Geometria
Ore 14:00, aula di Consiglio
I will talk about the singular Liouville equation on compact surfaces, that
is a second-order elliptic PDE with an exponential nonlinearity and a singular
term, and the singular Toda system, that is a system of two equations with
similar features. I will present some existence results based on variational
methods.
Ore 14:30, aula G
We study the dynamics of a soliton in the generalized NLS with a small
external potential epsilon V of Schwartz class.
We prove that there exists an effective mechanical system describing the
dynamics of the soliton and that, for any positive integer r,
the energy of such a mechanical system is almost conserved up to times of
order ε-r.
In the rotational invariant case we deduce that the true orbit of the soliton
remains close to the mechanical one up to times of order
ε-r.
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invitati a comunicare il proprio indirizzo di posta elettronica a
seminari@mat.uniroma1.it.
Il Direttore