### Seminari

### Prossimi Seminari

**Dealing with unreliable computing platforms at extreme scale**

Luc Giraud, INRIA (Inria Bordeaux – Sud-Ouest)

mercoledì 23 gennaio 2019 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO**Poroelasticity: Discretizations and fast solvers based on geometric multigrid methods**

Francisco José Gaspar Lorenz, Department of Applied Mathematics -Zaragoza University – Spain

giovedì 31 gennaio 2019 alle ore 14:00, Sala Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO**Application of Polyconvexity and multivariable convexity of energy potentials in nonlinear solid mechanics**

Javier Bonet, University of Greenwich

giovedì 14 febbraio 2019 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO

### Seminari Passati

**On the harmonicity of slice regular functions**

Cinzia Bisi, Università di Ferrara

giovedì 31 maggio 2018 alle ore 14:30, Aula Seminari III pianoABSTRACTI will start improving the definition of slice regular function over the quaternions given by Gentili-Struppa in 2006-2007.

Then, bringing new ideas to the theory, I will answer positively to the question: is a slice regular function over the quaternions (analogously to a holomorphic function over the complex) ”harmonic” in some sense, i.e. is it in the kernel of some order-two differential operator over the quaternions?

Finally, I will deduce novel integral formulas as applications.

This is part of a common project with J. Winkelmann.**La geometria delle piramidi egizie**

Corinna Rossi, Politecnico di Milano

mercoledì 30 maggio 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**Tales of Our Forefathers**

Barry Simon, California Institute of Technology

martedì 29 maggio 2018 alle ore 11:00, Sala Consiglio, 7 piano, Edificio La Nave, Via Bonardi 9ABSTRACTThis is not a mathematics talk but it is a talk for mathematicians. Too often, we think of historical mathematicians as only names assigned to theorems. With vignettes and anecdotes, I’ll convince you they were also human beings and that, as the Chinese say, “May you live in interesting times” really is a curse.**SPECTRAL THEORY, SUM RULES AND LARGE DEVIATIONS**

Barry Simon, California Institute of Technology

lunedì 28 maggio 2018 alle ore 16:30, Aula Chisini, Diparimento di Matematica, Via C. Saldini 50ABSTRACTAfter dening the spectral theory of orthogonal polynomials on the unit circle

(OPUC) and real line (OPRL), I’ll describe Verblunsky’s version of Szego’s

theorem as a sum rule for OPUC and the Killip-Simon sum rule for OPRL

and their spectral consequences. Next I’ll explain the original proof of Killip-Simon using representation theorems for meromorphic Herglotz functions.

Finally I’ll focus on recent work of Gamboa, Nagel and Rouault who obtain

the sum rules using large deviations for random matrices.**Matrix equation techniques for a class of PDE problems with data uncertainty**

Valeria Simoncini, Dipartimento di Matematica, Alma Mater Studiorum – Universita’ di Bologna

giovedì 24 maggio 2018 alle ore 11:30, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANOABSTRACTLinear matrix equations arise in an amazingly growing number of applications. Classically, they have been extensively encountered in Control theory and eigenvalue problems. More recently they have been shown to provide a natural platform in the discretization of certain partial differential equations (PDEs), both in the deterministic setting, and in the presence of uncertainty in the data. We first review some numerical techniques for solving various classes of large scale linear matrix equations commonly occurring in applications. Then we focus on recent developments in the solution of (systems of) linear matrix equations associated with the numerical treatment of various stochastic PDE problems.

Contact: paolo.zunino@polimi.it

**La Scoperta del Secolo – Perché le Onde Gravitazionali valgono un Nobel**

Luca Perri, L’Officina del Planetario

mercoledì 23 maggio 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**On the Hopf boundary lemma for quasilinear problems involving singular nonlinearities and applications**

Berardino Sciunzi, Università della Calabria

mercoledì 23 maggio 2018 alle ore 15:15, Aula seminari 3° pianoABSTRACTWe consider positive solutions to quasilinear elliptic problems with singular nonlinearities. We provide a Hopf type boundary lemma via a suitable scaling argument that allows to deal with the lack of regularity of the solutions up to the boundary. Symmetry and monotonicity properties of the solutions follows as an application.**Periodic solutions to perturbed Kepler problems**

Alberto Boscaggin, Università di Torino

martedì 22 maggio 2018 alle ore 15:15, Aula seminari 3° pianoABSTRACTAs well known (by third Kepler’s law) the Kepler problem has many periodic solutions with minimal period T (for any given T > 0). We will try to understand how many of them survive after a T-periodic external perturbation preserving the Newtonian structure of the equation. In doing this, we will be naturally led to the concept of generalized solution and to the theory of regularization of collisions in Celestial Mechanics. Joint work with Rafael Ortega (Granada) and Lei Zhao (Augsburg).