Notiziario Scientifico
Settimana dal 30 marzo al 5 aprile 2015
Martedì 31 marzo 2015
Martedì 31 marzo 2015
Martedì 31 marzo 2015
Mercoledì 01 aprile 2015
Mercoledì 01 aprile 2015
Mercoledì 01 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 14:00, aula B
Metodi matematici per le teorie cinetiche
In this talk I will discuss the dynamics of interacting fermionic systems in
the mean-field regime. Compared to the bosonic case, fermionic mean-field
scaling is naturally coupled with a semiclassical scaling, making the analysis
more involved. From a physical point of view, as the number of particles grows
one expects the quantum evolution of the system to be effectively described by
Hartree-Fock theory. The next degree of approximation is provided by a
classical effective dynamics, corresponding to the Vlasov equation.
I will consider initial data which are close to quasi-free states, both at zero
and at positive temperature, with an appropriate semiclassical structure. Under
some regularity assumptions on the interaction potential I will show that the
time evolution of such initial data stays close to a quasi-free state, with
reduced one-particle density matrix given by the solution of the time-dependent
Hartree-Fock equation. The result holds for all (semiclassical) times, and
gives effective bounds on the rate of convergence towards the Hartree-Fock
dynamics as the number of particles goes to infinity.
Ore 14:30, aula Dal Passo, Università di Roma Tor Vergata
Seminario di Equazioni Differenziali
In this talk I would like to discuss the homogenization problem for Hamilton-Jacobi equations,
in the case of Tonelli Hamiltonians which are invariant under the action of a discrete group.
This different point of view, besides providing a general setting that embraces previous results
in the literature (from the classical work by Lions, Papanicolaou and Varadhan to the more
recent one by Contreras, Iturriaga and Siconolfi), will allow us to get a clearer understanding
of the geometry of the limit space and of the structure of the homogenized problem.
Ore 15:00, aula di Consiglio
Seminario di Modellistica Differenziale Numerica
In an electromagnetic machine with permanent magnets the excitation field is
provided by a permanent magnet instead of a coil. The center of the generator,
the rotor, contains the magnet. Our optimization goal consists in finding the
minimum volume of the magnet which gives a desired electromotive force. This is
a standard optimization problem with PDE constraints. We propose a goal
oriented model order reduction approach to provide a reduced order surrogate
model for the parametrized PDE which then is utilized in the numerical
optimization. One important feature of the proposed scheme is the online update
of the basis functions which allows to avoid expensive offline stages.
Numerical tests will be provided in order to show the effectiveness of the
proposed method. Joint work with M. Hinze, O. Lass and S. Ulbrich.
Ore 14:30, aula di Consiglio
eminaio di Algebra e Geometria
A celebrated result by Poincaré states that a compact Riemann surface has a conformal
metric of constant curvature, unique up to rescaling and biholomorphisms. Clearly,
the case of genus 0 is not so exciting, being trivially solved by any Fubini-Study
metric on the complex projective line.
The problem becomes more interesting if we require such metrics to have conical singularities
of prescribed angles at a finite subset of n marked points. The case of negative and zero
curvature was settled by McOwen and Troyanov in 1989-1991: they established the existence
and uniqueness of such a metric in each conformal class.
The case of positive curvature is more delicate: existence and uniqueness results are known
for small angles (Troyanov), whereas non-uniqueness results are known in positive genus
(Bartolucci-De Marchis-Malchiodi).
In a joint work with D.Panov (still in progress), we determine for which angle assignment
there exists a surface of genus 0 with a metric of curvature 1 and conical singularities
of such prescribed angles (and non-coaxial holonomy).
Ore 14:30, aula G, Università di Roma Tre (via della Vasca Navale)
After the Higgs discovery one of the major goals of LHC is the measurement of
Higgs couplings. A special role is taken in this context by the trilinear Higgs
coupling whose measurement would shed light on the form of the Higgs potential.
The trilinear Higgs coupling can be measured in Higgs pair production processes.
In this talk I want to review the theoretical status of Higgs pair production
processes and discuss the accessibility of the trilinear Higgs coupling at the
LHC. Furthermore, I want to discuss extensions of the Standard Model and their
predictions for Higgs pair production processes.
Ore 16:00, aula C,
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