Notiziario Scientifico

Settimana dal 23 al 29 giugno 2014


Lunedì 23 giugno 2014
Ore 16:30, Aula 1B1, Dipartimento SBAI
Francois Murat (Università di Parigi VI)
Problemi ellitici semilineari con singularita in u=


Martedì 24 giugno 2014
Ore 14:00, Aula Picone
Seminario di Probabilità
Julien Reygner (Università di Parigi VI)
Multitype sticky particles and probabilistic solutions to hyperbolic systems of nonlinear PDEs
We study hyperbolic systems of nonlinear PDEs with monotone and bounded data. Without loss of generality, we assume that these data are cumulative distribution functions (CDFs) on the real line, and look for solutions that remain so at all time. Such solutions are called 'probabilistic solutions'. In the scalar case, it is known that the probabilistic solution can be approximated by the empirical CDF of a system of sticky particles introduced by Brenier and Grenier, that is described as follows: particles travel on the real line at constant velocity and stick into clusters at collisions, with conservation of mass and momentum. Stability estimates on the probabilistic solution in Wasserstein distance were obtained by Bolley, Brenier and Loeper. We introduce a multitype version of the sticky particle dynamics and use it to obtain the existence of a probabilistic solution for any choice of data, under a uniformly strict hyperbolicity assumption on the system. We then derive similar Wasserstein stability estimates. A key ingredient of our proof is a uniform L^p stability estimate on the evolution of the particle system.


Martedì 24 giugno 2014
Ore 14:30, Aula 311, Università di Roma III
Seminario di Fisica Matematica
Claudio Cacciapuoti (Università dell'Insubria)
Point-like limit for a NLS equation with spatially concentrated nonlinearity
The nonlinear Schrodinger (NLS) equation with spatially dependent nonlinearity describes systems in which the response of the medium to wave-function propagation is not homogeneous in space. I will consider a one-dimensional NLS equation in which the nonlinearity is strongly localized in space around a finite number of points. For suitable scaled, concentrated nonlinearities, I will discuss the convergence of the dynamics to the one generated by a NLS equation with point-like nonlinearities. The definition of the limit dynamics is mimicked on the case of a linear point potential (delta interaction). Nonlinear delta interactions in one and three dimensions, are well known and extensively studied models in mathematical physics. Our result represents a first attempt to justify such models in terms of the approximation through regularized dynamics. This is a joint work in collaboration with D. Finco, D. Noja, and A. Teta.


Martedì 24 giugno 2014
Ore 14:30, Aula Dal Passo, Università di Roma II
Seminario di Equazioni Differenziali
Yannick Sire (CNRS, Marsiglia)
On the fractional Yamabe problem
I will report on recent works related to prescribing a new notion of curvatures, interpolating somehow between several well-known curvatures. I will discuss several open problems and lines of research of interest in the field.


Mercoledì 25 giugno 2014
Ore 9:30, Aula Picone
Conference on Nonlinear Evolution Problems
9.30 - 10.00 Welcome address
10.00 - 10.40 Masayasu Mimura (Meiji University)
Spatio-temporal oscillations in the Keller-Segel system with logistic growth
10.50 - 11.30 Brian H. Gilding (Kuwait University)
One-dimensional free-boundary problems in inventory control
11.40 - 12.20 Jesus Hernandez (Universidad Autonoma de Madrid)
On linearized stability results for positive solutions to semilinear singular elliptic problems


Mercoledì 25 giugno 2014
Ore 14:30, Aula Picone
Conference on Nonlinear Evolution Problems
14.30 - 15.10 Danielle Hilhorst (Universite' Paris-Sud)
On the large time behavior of solutions of a nonlocal evolution equation
15.15 - 15.55 Robert Kersner (University of Pecs)
On a cross-diffusion PDE system
16.30 - 17.10 Corrado Mascia (Sapienza Università di Roma)
Hyperbolic variations of the Allen-Cahn equation
17.15 - 17.55 Adriano Pisante (Sapienza Università di Roma)
Allen-Cahn approximation of mean curvature flow on Riemannian manifolds}


Mercoledì 25 giugno 2014
Ore 16:00, Aula Dal Passo, Università di Roma II
Esteban Andruchow (Università di Buenos Aires)
Projections in Hilbert spaces with two norms
Let A be a positive injective operator in a Hilbert space (H, < . , . >), and denote by [ . , . ] the inner product defined by A: [f,g] = < Af,g > . A closed subspace S â H is called A-compatible if there exists a closed com- plement for S, which is orthogonal to S with respect to the inner product [ . , . ]. Equivalently, if there exists a necessarily unique bounded idempo- tent operator Q_S such that R(Q_S) = S, which is symmetric for this inner product. The compatible Grassmannian Gr_A is the set of all A-compatible sub- spaces of H. By parametrizing it via the one to one correspondence S < - > Q_S , this set is shown to be a differentiable submanifold of the Banach space of all bounded operators in H which are symmetric with respect to the form [ . , . ]. A Banach-Lie group acts naturally on the compatible Grassmannian, the group of all invertible operators in H which preserve the form [ . , . ]. For p between 1 and infinity, in the presence of a fixed [ . , . ]-orthogonal (direct sum) decomposition of H, H = S_0 + N_0, we study the restricted compatible Grassmannian (an analogue of the restricted, or Sato Grassmannian). This restricted compatible Grassmannian is shown to be a submanifold of the Banach space of p-Schatten operators which are symmetric for the form [ . , . ]. It carries the locally transitive action of the Banach-Lie group of invertible operators which preserve [ . , . ], and are of the form G = 1 + K, with K in the p-Schatten class. The connected components of this restricted Grassmannian are characterized by means of of the Fredholm index of pairs of projections. Finsler metrics which are isometric for the group actions are introduced for both compatible Grassmannians, and minimality results for curves are proved.


Giovedì 26 giugno 2014
Ore 9:00, Aula Picone
Conference on Nonlinear Evolution Problems
9.00 - 9.40 Hiroshi Matano (University of Tokyo)
Propagating terrace for multi-stable nonlinear diffusion equations
9.45 - 10.25 Mimmo Iannelli (Università di Trento)
A model for describing the structure and growth of epidermis
11.00 - 11.40 Shoshana Kamin (Tel Aviv University)
Prescribed conditions at infinity for parabolic equations
11.45 - 12.25 Roberto Natalini (Istituto per le Applicazioni del Calcolo "M. Picone", CNR)
Hyperbolic perturbations of scalar laws: from oil recovery to vasculogenesis


Giovedì 26 giugno 2014
Ore 9:30
Casa San Bernardo, via Laurentina 289
Workshop on "Ludics and Philosophy"
09h30 : Opening: Themes of these days
10h15 : Alain Lecomte: Ludics and modelisation of Socratic dialogues
11h15 : Michele Abrusci: Incompleteness theorems and Transcendental Syntax
12h00 : Mathieu Marion: Dialogue, dialectics, and inferentialism
14h30 : Alberto Naibo: From axioms to computation: A philosophical account of geometry of interaction
15h15 : Paolo Pistone: Rules, types and the transcendence of second order logic
16h15: Giuseppe Primiero: Resources based interpretation of Ludics
17h00 : General Discussion


Giovedì 26 giugno 2014
Ore 14:30, Aula Picone
Conference on Nonlinear Evolution Problems
14.30 - 15.10 Laurent Veron (Université Francois Rabelais)
Initial trace of positive solutions of weakly superlinear parabolic equations
15.20 - 16.00 Andrea Terracina (Sapienza Università di Roma)
Uniqueness and non-uniqueness results for entropy solutions of forward--backward parabolic problems
16.10 - 16.50 Michiel Bertsch (Università di Roma "Tor Vergata")
Travelling wave solutions of a system of PDE's


Venerdì 27 giugno 2014
Ore 9:00, Aula Picone
Conference on Nonlinear Evolution Problems
9.00 - 9.40 Wei-Ming Ni (East China Normal University and University of Minnesota)
Competition--diffusion systems
9.45 - 10.25 Lorenzo Giacomelli (Sapienza Università di Roma)
Well-posedness for the Navier-slip thin-film equation in complete wetting
11.00 - 11.40 Henri Berestycki (EHESS)
Propagation in non homogeneous media - the effect of geometry
11.45 - 12.25 Catherine Bandle (University of Basel)
Quasilinear elliptic and parabolic problems with a Hardy potential


Venerdì 27 giugno 2014
Ore 9:30
Casa San Bernardo, via Laurentina 289
Workshop on "Ludics and Philosophy"
09h30 : Laurent Keiff: Modalities, Proof theory and Ludics
10h15 : Frederic Nef: Relation and Connection
11h15 : Michele Basaldella: Ludics without designs
12h00 : Arnaud Valence: Towards a Transcendental Euristics
14h30 : Daniele Porello: TBA
15h15 : Pierre Livet: The notion of incompatibility in Brandom's inferentialism
16h15 : Samuel Tronçon: Ludics and Social Interaction
17h00 : General Discussion


Venerdì 27 giugno 2014
Ore 11:30, Aula D'Antoni, Università di Roma II
Seminario di Geometria Algebrica
Francesco Polizzi (Università della Calabria)
Fattorialita' di threefolds con singolarita' ordinarie
Presenterò alcuni nuovi risultati sulla fattorialità di threefolds in P^4 aventi solo singolarità ordinarie (tali cioè che il corrispondente cono tangente è un cono su una superficie liscia). Enuncerò poi una congettura che generalizza precedenti risultati ottenuti da Ciliberto-Di Gennaro e Cheltsov nel caso di threefolds nodali. Si tratta di un lavoro in collaborazione con A. Rapagnetta e P. Sabatino.


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