### Prossimi Seminari

**Asymptotic analysis of linear Moore-Gibson-Thompson equations**

Filippo Dell’Oro, Politecnico di Milano

mercoledì 29 marzo 2017 alle ore 15:15 precise, Aula seminari 3° piano**Un agguato e due errori. Comunicare contenuti di scienza e tecnologia: è possibile? Non è detto**

Federico Pedrocchi, Giornalista scientifico

mercoledì 29 marzo 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**Reduced basis methods for parametrized PDEs: how to enhance efficiency and accuracy in complex problems**

Andrea Manzoni , EPFL Losanna

lunedì 3 aprile 2017 alle ore 14:30, Aula Seminari ‘Saleri’ VI Piano MOX-Dipartimento di Matematica, Politecnico di Milano – Edificio 14**Las Meninas di Diego Velasquez: segno, proiezione, riflesso**

Luigi Cocchiarella, Politecnico di Milano

mercoledì 5 aprile 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**Regression analysis for compositional data from perspective of the logratio approach**

Eva Fiserova e Karel Hron, Palacky University, Olomouc, Czech Republic

giovedì 6 aprile 2017 alle ore 14:00 precise, Aula Seminari “F. Saleri” VI piano – MOX – Dipartimento di Matematica, Politecnico di Milano – Edificio 14**Proximity operator computation for large scale problems**

Jean-Christophe Pesquet, University Saclay

martedì 11 aprile 2017 alle ore 15:00 precise, Aula seminari 3° piano**Computational cardiac electrophysiology: motivations, mathematical models and scalable solvers**

Piero Colli Franzone, Università di Pavia, Dipartimento di Matematica

giovedì 20 aprile 2017 alle ore 14:00, Aula Seminari ‘Saleri’ VI Piano MOX-Dipartimento di Matematica, Politecnico di Milano – Edificio 14**Energy from ocean waves**

Giuseppe Passoni, POLITECNICO DI MILANO, Dipartimento di Elettronica Informazione e Bioingegneria

giovedì 27 aprile 2017 alle ore 14:00, Aula Seminari ‘Saleri’ VI Piano MOX-Dipartimento di Matematica, Politecnico di Milano – Edificio 14**Laser superintensi, materiali nanostrutturati, accelerazione di particelle: il ruolo della matematica**

Matteo Passoni, Politecnico di Milano

mercoledì 10 maggio 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**Oltre il nostro Sistema Solare: alla ricerca di un’altra Terra**

Barbara Negri , ASI Agenzia Spaziale Italiana

mercoledì 17 maggio 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**Iannis Xenakis: architetto della luce e del suono**

Alessandra Capanna, Università “La Sapienza” ? Roma

mercoledì 24 maggio 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**Leggere i dati per progettare le politiche pubbliche per il nuovo millennio: una sfida (im)possibile**

Giovanni Azzone – Piercesare Secchi, Politecnico di Milano

mercoledì 31 maggio 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, aula De Donato**Astronome del passato – Una, nessuna o centomila?**

Gabriella Bernardi, Giornalista scientifico

mercoledì 7 giugno 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21

### Seminari Matematici Politecnico di Milano

### Seminari Matematici Milano e dintorni

### Archivio Seminari

**RANDOM CRACKS IN SPACE**

WENDELIN WERNER, ETH Zürich

lunedì 27 marzo 2017 alle ore 16:30, Aula Chisini, via Saldini 50ABSTRACTABOUT THE SPEAKER: Wendelin Werner is a world renowned scientist, whose exciting work intertwines probability theory with mathematical physics and complex analysis. Werner is often motivated by problems in statistical physics which involve critical phenomena in the large scale behavior of complex multi-particle systems; such as those that arise in phase transitions and percolation. His profound work on stochastic Loewner evolution, the fractal geometry of two dimensional Brownian motion and conformal field theory earned Werner both the Fields medal and the SIAM Pólya Prize (together with collaborators Greg Lawler and Oded Schramm) in 2006. In addition, Werner is the recipient of the European Mathematical Society Prize (2000), the Fermat Prize (2001), the Jacques Herbrand Prize (2003), the Loève Prize (2005) and was inducted into the French Academy of Sciences in 2008. Werner received his Ph.D in 1993 from the Universitè Paris VI under the direction of Jean-François Le Gall and has held positions at the Cambridge University, Universitè Paris-Sud and Ecole Normale Supèrieure before being named Professor of Mathematics at ETH Zürich in 2013.**Un gioco cooperativo: lo scambio di donatori di rene**

Roberto Lucchetti, Politecnico di Milano

mercoledì 22 marzo 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**What’s in an envelope? Operator theory and numerical ranges**

Pamela Gorkin, Bucknell University, Pennsylvania

lunedì 20 marzo 2017 alle ore 16:00 precise, Sala di rappresentanza, Dipartimento di Matematica, Università degli Studi, Via C. Saldini 50**Quasi-optimality of nonconforming methods for linear variational problems**

Pietro Zanotti , Universita’ degli Studi di Milano

giovedì 16 marzo 2017 alle ore 11:00, Aula Seminari “Saleri” VI Piano MOX-Dipartimento di Matematica, Edificio 14 POLITECNICO DI MILANOABSTRACTWe consider the approximation of linear elliptic variational problems, symmetric for simplicity. According to the Cea’s lemma, conforming Galerkin methods for these problems are quasi-optimal. Conversely, a simple argument reveals that classical nonconforming methods do not enjoy such property. Motivated by this observation, we derive necessary and sufficient conditions for quasi-optimality, within a large class of methods. Moreover, we identify the quasi-optimality constant and discuss its ingredients. In the second part of the talk, we present a detailed construction of two quasi-optimal nonconforming methods for a model problem and show that the corresponding quasi-optimality constants are bounded in terms of the shape parameter of the underlying meshes. This is a joint work with Andreas Veeser.

contact:

paola.antonietti@polimi.it

simona.perotto@polimi.it

**Nonlinear and Nonlocal Degenerate Diffusions on Bounded Domains**

Matteo Bonforte, Universidad Autonoma de Madrid

giovedì 16 marzo 2017 alle ore 11:00 precise, Aula seminari 3° pianoABSTRACTWe investigate quantitative properties of nonnegative solutions to a nonlinear fractional diffusion equation, of degenerate type, posed in a bounded domains, with appropriate homogeneous Dirichlet boundary conditions. The diffusion is driven by a quite general class of linear operators that includes the three most common versions of the fractional Laplacian in a bounded domain with zero Dirichlet boundary conditions; many other examples are included. The nonlinearity is assumed to be increasing and is allowed to be degenerate, the prototype being convex powers. We will present some recent results about existence, uniqueness and a priori estimates for a quite large class of very weak solutions, that we call weak dual solutions.

We will devote special attention to the regularity theory: decay and positivity, boundary behavior, Harnack inequalities, interior and boundary regularity, and asymptotic behavior. All this is done in a quantitative way, based on sharp a priori estimates. Although our focus is on the fractional models, our techniques cover also the local case, and provide new results even in this setting.

A surprising instance of this problem is the possible presence of nonmatching powers for the sharp upper and lower boundary behavior. This unexpected phenomenon is a completely new feature of the nonlocal nonlinear structure of this model, and it is not present in the elliptic case.

The above results are contained on a series of recent papers in collaboration with A. Figalli, Y. Sire, X. Ros-Oton and J. L. Vazquez.**La matematica dei terremoti.**

Alfio Quarteroni, EPFL— Politecnico di Milano (on leave)

mercoledì 15 marzo 2017 alle ore 12:15, Campus Leonardo, via Bonardi 9, Edificio 14 (Nave), aula B21**Spectra, automata and discrete analogues of the KdV equation**

Andrzej Zuk , C.N.R.S. France et Université Paris 7

lunedì 13 marzo 2017 alle ore 11:30 precise, Aula seminari 6° pianoABSTRACTBox-Ball systems are discrete analogues of the KdV equation. We prove that their evolution can be described by automata. With these automata we associate self-adjoint operators. We relate spectral properties of these operators with L^2 Betti numbers of closed manifolds.**Maximum principle and the principal eigenvalue, a long story**

Isabeau Birindelli, Università di Roma La Sapienza

giovedì 9 marzo 2017 alle ore 17:00 precise, Aula Chisini, Dipartimento di Matematica, Via Saldini 50ABSTRACTThe link between the principal eigenvalue and the maximum principle has been made very clear since the works of Protter – Weinberger, Pucci and Berestycki-Nirenberg-Varadhan. Its consequences are important and go from regularity of solutions to their very existence.

I will start by giving a survey of this rich field in the classical case of the second order uniformly elliptic operators. Then I will go on describing what and how some of these results extend or not to non linear operators and to degenerate elliptic operators.