Notiziario Scientifico

Notiziario dei seminari di carattere matematico
a cura del Dipartimento di Matematica G. Castelnuovo, Sapienza Università di Roma

Settimana dal 29-03-2021 al 04-04-2021

Lunedì 29 marzo 2021
Ore 14:30, https://meet.google.com/nie-attq-ged
seminario di Analisi Matematica
Piermarco Cannarsa (U. Roma Tor Vergata)
Long time behaviour of solutions to Hamilton-Jacobi equations for sub-Riemannian control systems
Sub-Riemannian systems are an important class of nonlinear control systems with linear dependence on controls. Controllability properties for such systems are derived by the so-called Lie Algebra rank condition on the associated family of vector fields. We will discuss the long-time average behaviour of the value function of optimal control problems for sub-Riemannian systems, which cannot be addressed by classical weak KAM theory as the Hamiltonian fails to be coercive in the momentum variable.

Mercoledì 31 marzo 2021
Ore 14:30, https://meet.google.com/pip-kvzt-fkz, Dipartimento di Fisica, Sapienza Università di Roma
Seminario delle Meccaniche
Valerio Lucarini (University of Reading, UK)
Dynamical Landscape and Multistability of a Climate Model
We study the multistability of the Earth’s climate using a numerical model forced by stochastic fluctuations of the solar irradiance. In the weak-noise limit, large deviation laws define the invariant measure, the statistics of escape times from the competing basins of attraction, and the instantons. The system lives in the dynamical landscape defined by the Graham's quasipotential, whose properties are reconstructed using both a suite of simulations and manifold learning from a single long trajectory. We draw a link between macroscopic properties of the climate such the ocean heat transport and of the hydrological cycle and the topography of the dynamical landscape.

Mercoledì 31 marzo 2021
Ore 16:00, Online Seminar, Dipartimento di Matematica, Università di Roma "Tor Vergata"
Seminario di Algebre di Operatori
Gerardo Morsella (Università di Roma "Tor Vergata")
UV and IR finiteness on quantum spacetime through perturbative algebraic QFT
Local QFT on Doplicher-Fredenhagen-Roberts quantum spacetime is equivalent to a non-local QFT on ordinary (commutative) spacetime, which has quite generally a better UV behavior in perturbation theory, but for which the control of the adiabatic limit is problematic. I will show that the adaptation of the methods of perturbative QFT, originally developed for local QFT on ordinary spacetimes, to QFT on quantum spacetime yields a non-local UV-finite theory which enjoys some remnants of causality. This is sufficient to prove the existence of the adiabatic limit of vacuum expectation values of interacting observables. (Joint work with S. Doplicher and N. Pinamonti.) Link Seminario
Per informazioni, rivolgersi a: v.morinelli@gmail.com

Giovedì 01 aprile 2021
Ore 14:00, Seminario online su questo link, Dipartimento di Matematica, Università di Roma "Tor Vergata"
Seminario di Analisi Matematica
Louis Jeanjean (Universita' di Bourgogne Franche-Comté)
Prescribed norm solutions of Schrödinger equations with mixed power nonlinearities
In this talk, I will present some recent results concerning the existence of prescribed norm solutions in problems where the associated nonlinearity is the sum of two powers, one which is mass-subcritical and one mass-supercritical. This leads to consider a constrained variational problem presenting a so-called convex-concave geometry. The issues of existence, multiplicity and orbital stability of solutions will be addressed with a special emphasize on the cases where the mass-supercritical power is Sobolev critical. The content of this talk is based on some jointed work with J. Jendrej, T. T. Le and N. Visciglia.
NB:This talk is part of the activity of the MIUR Excellence Department Project MATH@TOV CUP E83C18000100006

Per informazioni, rivolgersi a: molle@mat.uniroma2.it

Giovedì 01 aprile 2021
Ore 14:30, Il seminario sarà tenuto in modalità telematica, Dipartimento di Matematica e Fisica, Università degli Studi RomaTre, Largo San Leonardo Murialdo 1
Seminario di Geometria
Simone Diverio (Sapienza Università di Roma)
Negative curvature and Kobayashi hyperbolicity
Negativity of the holomorphic sectional curvature is a sufficient condition which insures that a compact complex manifold is Kobayashi hyperbolic, but it is far from being necessary. After reviseing the essential notions and concepts of curvature for Hermitian and/or Kahler manifolds, and how they are linked with Kobayashi hyperbolicity, we shall quantify the above-mentioned lack of necessity and illustrate it also via examples. In the second part of the talk, we shall explain how it is possible, under the stronger hypothesis of negativity of the holomorphic sectional curvature, to prove a longstanding conjecture by Kobayashi stating that a compact Kobayashi hyperbolic Kahler manifold is projective and canonically polarized (works of Wu-Yau, Tosatti-Yang, Diverio-Trapani, and Guenancia).
Per partecipare al seminario cliccare sul seguente link Teams

Giovedì 01 aprile 2021
Ore 14:30, canale youtube IAC CNR https://www.youtube.com/watch?v=OGyylOkOIVw, Istituto per le Applicazioni del Calcolo - Consiglio Nazionale delle Ricerche
Seminari generali dell'IAC 2021
Maurizio Ceseri (Istituto per le Applicazioni del Calcolo - Consiglio Nazionale delle Ricerche)
Mathematical Models for Cultural Heritage applications
This talk will outline some of the major problems involved in the conservation of Cultural Heritage and building materials. An example of such a problems is the formation of salt crystals inside porous stones. Salt is present in building stones as free ions dissolved in water. Water penetrates the stones by capillarity. Once salt reaches a supersaturation level, it forms crystals that have impacts on the deterioration of the material even leading to the breakage of the stone. Another example is the formation of iron rings, the so-called Liesegang rings, in porous stones as the result of a sequence of reactions and precipitation of carbonate compounds and iron ions dissolved in water. During the talk, we will outline the role of mathematical models to understand the damage processes of monumental stones and how they will support restoration and conservation activities.
Per informazioni, rivolgersi a: roberto.natalini@cnr.it

Le comunicazioni relative a seminari da includere in questo notiziario devono pervenire esclusivamente mediante apposita form da compilare online, entro le ore 24 del giovedì precedente la settimana interessata. Le comunicazioni pervenute in ritardo saranno ignorate. Per informazioni, rivolgersi all'indirizzo di posta elettronica seminari@mat.uniroma1.it.
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