### Seminari

### Prossimi Seminari

**Serrin’s overdetermined problem on the sphere**

Tobias Weth, Goethe-Universitat Frankfurt

lunedì 23 aprile 2018 alle ore 16:00, Aula 6° piano**A review on some fourth order problems on manifolds**

Zindine Djadli, Université Grenoble Alpes

martedì 24 aprile 2018 alle ore 15:15, Sala del Consiglio 7° piano**Computing disconnected bifurcation diagrams of partial differential equations**

Patrick Farrell, Mathematical Institute, Oxford

giovedì 26 aprile 2018 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO**Large deviations for the stochastic Allen-Cahn approximation of the mean curvature flow**

Adriano Pisante, Università degli Studi di ROMA “La Sapienza”

giovedì 3 maggio 2018 alle ore 15:15, Aula seminari 3° piano**Heat content asymptotics of bounded domains**

Alessandro Savo, Università La Sapienza Roma

martedì 8 maggio 2018 alle ore 15:15, Aula Seminari 3° piano**Computer, simulazioni ed esperimenti: all’alba di un nuovo metodo sperimentale?**

Viola Schiaffonati, Politecnico di Milano

mercoledì 9 maggio 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**Development of a HPC library for the parallel implementation of p-adaptive discontinuous finite element methods applied to geophysical flows.**

Stella Paronuzzi Ticco, OGS Trieste and Laboratorio MOX Milano

giovedì 10 maggio 2018 alle ore 00:00, Aula Seminari ‘Saleri’ VI Piano MOX-Dipartimento di Matematica, Politecnico di Milano – Edificio 14**Recent progress on rationality problems**

Arnaud Beauville, Université de Nice

lunedì 14 maggio 2018 alle ore 15:30, Sala di Rappresentanza, Università di Milano, Via C. Saldini 50, Milano**Modellazione paziente specifica in emodialisi**

Maria Laura Costantino, Politecnico di Milano

mercoledì 16 maggio 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**Maximally writhed real algebraic knots and links**

Grigory Mikhalkin, Université de Genève

giovedì 17 maggio 2018 alle ore 17:00 precise, Sala di Rappresentanza, Università di Milano, Via C. Saldini 50, Milano**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**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 MILANO**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**Missione Planck, l’immagine dell’universo neonato**

Marco Bersanelli, Università degli Studi di Milano

mercoledì 6 giugno 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**Biomechanical modeling of the heart, and cardiovascular system – From sarcomeres to organ / system, with experimental assessments and patient-specific clinical validations**

Dominique Chapelle, M3DISIM, INRIA – Paris – France

giovedì 7 giugno 2018 alle ore 10:30, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO**Inverse Problems for the Cardiac System**

Philippe Moireau, M3DISIM, INRIA – Paris – France

giovedì 7 giugno 2018 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO**Joint and Individual Variation Explained**

Steve Marron, Department of Statistics and O.R., University of North Carolina

lunedì 18 giugno 2018 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO**TBA**

Raymond Ogden, School of Mathematics and Statistics, University of Glasgow

giovedì 28 giugno 2018 alle ore 14:00, Aula Consiglio VII piano

### Seminari Passati

**Ricostruire l’invisibile…fantasmi permettendo**

Paolo Dulio, Politecnico di Milano

mercoledì 18 aprile 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**Monotonicity formulas in potential theory with applications**

Lorenzo Mazzieri, Università degli Studi di Trento

mercoledì 18 aprile 2018 alle ore 15:15, Aula seminari 3° pianoABSTRACTWe 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).**Nonlinear scalar field equations with competing potentials**

Riccardo Molle, Università di Roma “Tor Vergata”

martedì 17 aprile 2018 alle ore 15:15, Aula 6° pianoABSTRACTIn 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.**Mixed finite elements and adaptive schemes for eigenvalue problems**

Daniele Boffi, Dipartimento di Matematica “F. Casorati”, Università di Pavia

giovedì 12 aprile 2018 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANOABSTRACTWe review a posteriori error analysis and adaptive schemes for the approximation of eigenvalue problems arising from partial differential equations. Our ultimate goal is the design of adaptive schemes for the approximation of the eigenmodes associated with Maxwell’s equations. It is well known that the Maxwell eigenvalue problem can be analyzed with the help of suitable mixed formulations. Taking advantage of this remark, we can prove the convergence with optimal rate for the edge finite element approximation of the Maxwell eigenvalue problem. In

three dimensions, the result is not a trivial extension of the analysis previously performed for the approximation of the Laplace eigenproblem in mixed form. Particular attention is paid to the case of multiple eigenvalues and clusters of eigenvalues.

Contact: christian.vergara@polimi.it

**Non-canonical embeddings and a canonical torsion-free covering for Mori Dream Spaces**

Michele Rossi, Università di Torino

giovedì 12 aprile 2018 alle ore 14:30 precise, Aula seminari del terzo pianoABSTRACTThe talk will be divided in two parts, approximately 45 minutes each; the first part is intended to be an introduction to the more technical second part; there will be a brief break between the two parts.

In the first part of this talk I will recall a standard construction of an (almost)-canonical toric embedding of a (non-necessarily projective) Mori Dream Space (MDS), starting from its Cox ring. Moreover I will recall some notation about the GKZ-decomposition of the pseudo-effective and the moving cone of a MDS. In the second part we will see some obstruction to extending Hu-Keel birational geometric results to the non-projective setup. Then I will show how recent results, jointly obtained with L. Terracini for $\Q$-factorial complete toric varieties, can be easily extended to a general MDS, producing a projective embedding of every MDS of Picard number less than or equal to 2 and a canonical covering space, unramified in codimension 1, of a given MDS, which is still a MDS admitting a torsion-free class group.

In principle, an application of such a covering construction is that the Cox ring of a MDS, which is in general graded over a class group with non trivial torsion part, could be described in terms of the Cox ring of its canonical covering, which is now graded over a torsion-free class group. This is a work in progress.

**Cosa possono insegnarci i Bitcoin?**

Matteo Bedini, Numerix

mercoledì 11 aprile 2018 alle ore 12:15, Politecnico di Milano Campus Bonardi Edificio14 aula B21**Nonlinear Schrödinger equations on branched structures: the role of topology in the existence of ground states**

Enrico Serra, Politecnico di Torino

mercoledì 11 aprile 2018 alle ore 11:15, Aula seminari 3° pianoABSTRACTWe 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.**The Black-Litterman Model and Views from a Reverse Optimization Procedure: An Out-of-Sample Performance Evaluation**

Erindi Allaj, Università degli Studi di Firenze

martedì 10 aprile 2018 alle ore 12:15 precise, Aula Seminari del Terzo PianoABSTRACTThe Black-Litterman (BL) model has been proposed as a valid solution to the problem of the estimation error in the parameter estimates of the Mean-Variance (MV) model. However, very little research has been done in order to facilitate the application of the BL model and to empirically test the performance of the BL model. The paper contributes to the existing literature by proposing an intuitive and easy application of the BL model. To this purpose, we suggest a novel approach to specify the investors views in the BL model. These views are derived by using a reverse optimization procedure similar to that used by the BL model in deriving the implied equilibrium expected excess returns. The second issue is addressed by empirically examining the out-of-sample performance of the BL model with respect to other asset allocation strategies. These strategies are given by the Sample MV (SMV), Minimum-Variance (MinV), Naive, Risk-Parity (RP), Capital Asset Pricing Model (CAPM), Strategic and the Bayesian strategy. In our empirical analysis, we also consider the reformulated BL model proposed by Allaj (2013) (BLEA model). Overall our results suggest that the BL model is a valid asset allocation strategy.