Adriano Pisante, Università degli Studi di ROMA "La Sapienza" , Large deviations for the stochastic Allen-Cahn approximation of the mean curvature flow, Thursday, May 03, 2018, time 15:15, Aula seminari 3° piano
Abstract:Abstract:
We consider the sharp interface limit for the Allen-Cahn equation on the three dimensional torus with deterministic initial condition and deterministic or stochastic forcing terms. In the deterministic case, we discuss the convergence of solutions to the mean curvature flow, possibly with a forcing term, in the spirit of the pioneering work of Tom Ilmanen (JDG '93). In addition we analyze the convergence of the corresponding action functionals to a limiting functional described in terms of varifolds. In the second part I will comment on related results for the stochastic case, describing how this limiting functional enters in the large deviation asymptotics for the laws of the corresponding processes in the joint sharp interface and small noise limit.

Zindine Djadli, Université Grenoble Alpes, A review on some fourth order problems on manifolds, Tuesday, April 24, 2018, time 15:15, Sala del Consiglio 7° piano
Abstract:Abstract:
I will review some recent works on some non linear problem on manifolds, mostly in conformal geometry. This seminar is organized within the PRIN 2015 Research project «Variational methods, with applications to problems in mathematical physics and geometry» Grant Registration 2015KB9WPT_010, funded by MIUR – Project coordinator Prof. Gianmaria Verzini

Tobias Weth, Goethe-Universitat Frankfurt, Serrin's overdetermined problem on the sphere, Monday, April 23, 2018, time 16:00, Aula 6° piano
Abstract:Abstract:
In this talk, I will discuss Serrin's overdetermined boundary value problem \begin{equation*} -\Delta\, u=1 \quad \text{ in $\Omega$},\qquad u=0, \; \partial_\eta u=\textrm{const} \quad \text{on $\partial \Omega$} \end{equation*} in subdomains $\Omega$ of the round unit sphere $S^N \subset {\mathbb R}^{N+1}$, where $\Delta$ denotes the Laplace-Beltrami operator on $S^N$. We call a subdomain $\Omega$ of $S^N$ a Serrin domain if it admits a solution of this overdetermined problem. In our main result, we construct Serrin domains in $S^N$, $N \ge 2$ which bifurcate from symmetric straight tubular neighborhoods of the equator. By this we complement recent rigidity results for Serrin domains on the sphere. This is joint work with M.M.Fall and I.A.Minlend (AIMS Senegal). This seminar is organized within the PRIN 2015 Research project «Variational methods, with applications to problems in mathematical physics and geometry» Grant Registration 2015KB9WPT_010, funded by MIUR – Project coordinator Prof. Gianmaria Verzini

Lorenzo Mazzieri, Università degli Studi di Trento, Monotonicity formulas in potential theory with applications, Wednesday, April 18, 2018, time 15:15, Aula seminari 3° piano
Abstract:Abstract:
We present an overview of some new monotonicity formulas, holding in the realm of linear and nonlinear potential theory, together with their main applications to several domains of investigation. These are ranging from the theory of overdetermined boundary value problems in the classical Euclidean setting, to the classification of static black holes in general relativity and to the geometry of manifolds with nonnegative Ricci curvature. (Joint works with V. Agostiniani, M. Fogagnolo and A. Pinamonti).

Riccardo Molle, Università di Roma "Tor Vergata", Nonlinear scalar field equations with competing potentials, Tuesday, April 17, 2018, time 15:15, Aula 6° piano
Abstract:Abstract:
In this talk a class of nonlinear elliptic equations on R^N is presented. These equations come from physical problems, where a potential interacts with the bumps in the solutions. We first discuss the interactions and present some old and new results; then we consider competing potentials, showing in particular a theorem on the existence of infinitely many positive bound state solutions. Finally, we present some examples on existence/non existence of a ground state solution, when the theorem applies.

Enrico Serra, Politecnico di Torino, Nonlinear Schrödinger equations on branched structures: the role of topology in the existence of ground states, Wednesday, April 11, 2018, time 11:15, Aula seminari 3° piano
Abstract:Abstract:
We describe some results on the existence or nonexistence of ground states of prescribed mass for the nonlinear Schrödinger equation on noncompact metric graphs. We will highlight the role played by the topology of the graph in all the existence results, in the cases of L^2 subcritical and critical power nonlinearity. In particular, in the critical case, a key role is played by a thorough analysis of the Gagliardo-Nirenberg inequalities on metric graphs and by estimates of their best constants. Most of the techniques are new and suited to the investigation of variational problems on metric graphs.