Direttore Vicario: Prof. Gabriele Grillo
Responsabile Gestionale: Dr.ssa Franca Di Censo
﻿
• Uno spettacolo in fuga: note sull’esperienza di Infinities di J.D Barrow e Luca Ronconi
8 marzo 2021 - ore 18.30

• EpiMOX
Un nuovo strumento per l'analisi dei dati della epidemia di CoViD-19 in Italia

### Prossimi Eventi

•  mar 04 gio 2021 MOX Colloquia Charbel Farhat, Computational Mechanics for Landing on Mars,  04-03-2021, ore 17:00

• MOX Colloquia
• Charbel Farhat
• Stanford University (USA)
• Computational Mechanics for Landing on Mars
• Giovedì 4 marzo 2021 alle ore 17:00
• Online seminar: mox.polimi.it/elenco-seminari/?id_evento=2035&t=763724
• Abstract
Current technology for decelerating a spacecraft from the high speed of atmospheric entry to the final stages of landing on Mars is based on parachute systems and dates back to NASA’s Viking Program. To enable future exploration missions featuring sophisticated robots and safely land heavier spacecraft on Mars, it must be advanced to a new level of performance at supersonic speeds. For this purpose, larger than before high-speed parachutes and inflatable drag devices are needed. Recently, it has become clear that the design, development, and maturing of such devices for future use at Mars cannot be performed by relying only on flight tests. It requires guidance from predictive simulations based on a high-fidelity, multi-disciplinary computational model for parachute inflation dynamics (PID) and drag prediction. The development of such a model is a formidable challenge. It must be able to predict various instabilities of a parachute such as flutter and pulsation, and assess the influence on its performance of several factors including material and geometric porosities, and the influence of temperature and strain rate on the stress field experienced in the supersonic regime. This lecture will discuss an ongoing effort at Stanford University, in collaboration with NASA and the Jet Propulsion Laboratory, for the development of such a computational model and some associated computational innovations. These include: a computationally tractable, data-driven framework for nonlinear, dynamic, multiscale modeling of membrane woven fabrics; a discrete-event-free, spurious-oscillation-free, and total variation diminishing embedded (immersed) boundary method for highly nonlinear fluid-structure interaction problems; a homogenization approach with subgrid scale modeling for treating porous wall boundary conditions; an energy-conserving, second-order accurate approach for enforcing transmission conditions at the interface between fluid and structural representations of disparate spatial dimensions; and a fast, massively parallel, load-balanced, adaptive mesh refinement methodology for tracking wall boundaries, boundary layers, and flow features such as shocks and wakes in an embedding domain. The lecture will report on some validation results for the simulation of the supersonic inflation dynamics of the parachute that landed Curiosity Rover on August 6, 2012. It will also highlight outstanding mathematical and numerical challenges associated with the simulation of PID from an initial condition where the parachute geometry is at bag strip, and with time-step restrictions induced by rapidly evolving fluid/structure interfaces.
Work in collaboration with Phil Avery, Jonathan Ho, Daniel Huang, Sebastian Grimberg.
Contact: Alfio Quarteroni, alfio.quarteroni@polimi.it
• Charbel Farhat

Charbel Farhat is the Vivian Church Hoff Professor of Aircraft Structures, Chairman of the Department of Aeronautics and Astronautics, and Director of the Stanford-KACST Center of Excellence for Aeronautics and Astronautics at Stanford University. His research interests are in computational engineering sciences for the design and analysis of complex systems in aerospace, mechanical, and naval engineering. He is a Member of the National Academy of Engineering, a Member of the Royal Academy of Engineering (UK), a Member of the Lebanese Academy of Sciences, a Doctor Honoris Causa from Ecole Centrale de Nantes, a Doctor Honoris Causa from Ecole Normale Supérieure Paris-Saclay, a designated ISI Highly Cited Author, and a Fellow of AIAA, ASME, IACM, SIAM, USACM, and WIF. He has trained more than 90 PhD and post-doctoral students. For his research on aeroelasticity, aeroacoustic scattering, CFD, dynamic data-driven systems, fluid-structure interaction, high performance computing, and model reduction, he has received many professional and academic distinctions including: the Ashley Award for Aeroelasticity and the Structures, Structural Dynamics and Materials Award from AIAA; the Lifetime Achievement Award and the Spirit of St Louis Medal from ASME; the Gordon Bell Prize and the Sidney Fernbach Award from IEEE; the Gauss-Newton Medal from IACM; the Grand Prize from the Japan Society for Computational Engineering Science; and the John von Neumann Medal from USACM. He was knighted in France in the Order of Academic Palms, appointed on the Scientific Advisory Board of the US Air Force, and selected by the US Navy recruiters as a Primary Key-Influencer and flown by the Blue Angels.
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 05 ven 2021 MOX Seminar Chiara Bartolucci, Novel Computational Model of Human Ventricular Action Potential for Investigate the Extracellular Calcium Effects,  05-03-2021, ore 11:00

• MOX Seminar
• Chiara Bartolucci
• Univ. of Bologna, Dept. of Electrical, Electronic and Information Engineering "Guglielmo Marconi"
• Novel Computational Model of Human Ventricular Action Potential for Investigate the Extracellular Calcium Effects
• Venerdì 5 marzo 2021 alle ore 11:00
• Online seminar: mox.polimi.it/elenco-seminari/?id_evento=2027&t=763721
• Abstract
The importance of electrolyte concentrations for the cardiac function is well established. Electrolyte variations can lead to arrhythmias onset, due to their important role in the action potential (AP) genesis and in maintaining cell homeostasis. However, most of the human AP computer models available in the literature were developed with constant electrolyte concentrations, and fail to simulate physiological changes induced by electrolyte variations. This is especially true for Ca2+, even in the most widely used models in cardiac electrophysiology.

The new human ventricular model (BPS2020, [1]), based on O’Hara-Rudy (ORd, [2]) model, aims to correct simulate changes due to electrolytes and answer the question: "which are the quantitative contributions of the mechanisms involved in the relationship between extracellular calcium concentration [Ca2+]o and the AP?"[3], using human-based modeling and simulations since they could provide useful support to investigate this phenomenon.

From earlier studies, it is well known that the L-type Ca2+ current (ICaL) is the ionic current mainly affected by [Ca2+]o changes. In particular, calcium-dependent inactivation (CDI) seems to play the most significant role. For this reason, the main changes needed with respect to ORd are: (i) increased sensitivity of ICaL current inactivation to [Ca2+]o; (ii) a single compartment description of the sarcoplasmic reticulum; iii) the replacement of Ca2+ release.

BPS2020 can simulate the physiological APD-[Ca2+]o relationship, while also retaining the well-reproduced properties of ORd (APD rate dependence at [K+]o=4mM, restitution, accommodation, and current block effects). We also used BPS2020 to generate an experimentally-calibrated population of models to investigate: (i) the occurrence of repolarization abnormalities in response to hERG current block; (ii) the rate adaptation variability; (iii) the occurrence of alternans and delayed after-depolarizations at fast pacing. Our results indicate that we successfully developed an improved version of ORd, which can be used to investigate electrophysiological changes and pro-arrhythmic abnormalities induced by electrolyte variations and current block at multiple rates and at population level.

[1] Bartolucci C, Passini E, Hyttinen J, Paci M, Roth BJ. Simulation of the Effects of Extracellular Calcium Changes Leads to a Novel Computational Model of Human Ventricular Action Potential With a Revised Calcium Handling 2020;11:1-20. doi:10.3389/fphys.2020.00314.

[2] O’Hara T, Virág L, Varró A, Rudy Y. Simulation of the undiseased human cardiac ventricular action potential: Model formulation and experimental validation. PLoS Comput Biol 2011;7.

[3] Bartolucci C, Paci M, Severi S. Investigation of the Extracellular Calcium Effects on Action Potential using the Most Recent Human Ventricular Cell Models. 2020 Comput Cardiol Conf 2020;47:7-10. doi:10.22489/cinc.2020.296.

Contatto: francesco.regazzoni@polimi.it
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 08 lun 2021 Seminar Israel Michael Sigal, Some Mathematical Problems of Quantum Mechanics,  08-03-2021, ore 16:00

• Seminar
• Israel Michael Sigal
• University of Toronto, ON, Canada
• Some Mathematical Problems of Quantum Mechanics
• Lunedì 8 marzo 2021 alle ore 16:00
• online
• Abstract
I will review some recent results on quantum-mechanical many-body problem and formulate some open problems.
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 10 mer 2021 Seminar Giulio Ballio, Gli errori umani nell'Ingegneria delle Strutture: imparare dal passato,  10-03-2021, ore 12:15

• Seminar
• Giulio Ballio
• Politecnico di Milano
• Gli errori umani nell'Ingegneria delle Strutture: imparare dal passato
• Mercoledì 10 marzo 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 16 mar 2021 Seminar Guido De Philippis, (Boundary) Regularity for area minimizing surfaces,  16-03-2021, ore 17:00

• Seminar
• Guido De Philippis
• Courant Institute of Mathematical Sciences
• (Boundary) Regularity for area minimizing surfaces
• Martedì 16 marzo 2021 alle ore 17:00
• On line
• Abstract
Plateau problem consists in finding a surface of minimal area among the ones spanning a given curve. It is among the oldest problem in the calculus of variations and its study lead to wonderful development in mathematics.
Federer and Fleming integral currents provide a suitably weak solution to the Plateau problem in arbitrary Riemannian manifolds, in any dimension and
co-dimension. Once this week solution has been found a natural question consists in understanding whether it is classical one. i.e. a smooth minimal surface. This is the topic of the regularity theory, which naturally splits into interior regularity and boundary regularity.
After the monumental work of Almgren, revised by De Lellis and Spadaro, interior regularity is by now well understood. Boundary regularity is instead less clear and some new phenomena appear.
Aim of the talk is to give an overview of the problem and to present some boundary regularity results we have obtained in the last years.

• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 17 mer 2021 Seminar Francesco Belgiorno, Buchi neri e campi gravitazionali estremi,  17-03-2021, ore 12:15

• Seminar
• Francesco Belgiorno
• Politecnico di Milano
• Buchi neri e campi gravitazionali estremi
• Mercoledì 17 marzo 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 17 mer 2021 Seminar Oliver Roth, A new Schwarz-Pick Lemma at the boundary and rigidity of holomorphic maps,  17-03-2021, ore 17:00

• Seminar
• Oliver Roth
• University of Wuerzburg
• A new Schwarz-Pick Lemma at the boundary and rigidity of holomorphic maps
• Mercoledì 17 marzo 2021 alle ore 17:00
• On line
• Abstract
We establish several invariant boundary versions of the (infinitesimal) Schwarz-Pick lemma for conformal pseudometrics on the unit disk and for holomorphic selfmaps of strongly convex domains in CN in the spirit of the boundary Schwarz lemma of Burns-Krantz.

Firstly, we focus on the case of the unit disk and prove a general boundary rigidity theorem for conformal pseudometrics with variable curvature. In its simplest cases this result already includes new types of boundary versions of the lemmas of Schwarz-Pick, Ahlfors-Schwarz and Nehari-Schwarz. The proof is based on a new Harnack-type inequality as well as a boundary Hopf lemma for conformal pseudometrics which extend earlier interior rigidity results of Golusin, Heins, Beardon, Minda and others. Secondly, we prove similar rigidity theorems for sequences of conformal pseudometrics, which even in the interior case appear to be new. For instance, a first sequential version of the strong form of Ahlfors' lemma is obtained.

As an auxiliary tool we establish a Hurwitz-type result about preservation of zeros of sequences of conformal pseudometrics.

Thirdly, we apply the one-dimensional sequential boundary rigidity results together with a variety of techniques from several complex variables to prove a boundary version of the Schwarz-Pick lemma for holomorphic maps of strongly convex domains in $\C^N$ for $N>1$.

• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mar 24 mer 2021 Seminar Camilla Colombo, Progetto COMPASS: Control for Orbit Manoeuvring Through Perturbations for Application to Space Systems,  24-03-2021, ore 12:15

• Seminar
• Camilla Colombo
• Politecnico di Milano
• Progetto COMPASS: Control for Orbit Manoeuvring Through Perturbations for Application to Space Systems
• Mercoledì 24 marzo 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mag 05 mer 2021 Seminar Marco Bramanti, La delta di Dirac: storia di un mostro,  05-05-2021, ore 12:15

• Seminar
• Marco Bramanti
• Politecnico di Milano
• La delta di Dirac: storia di un mostro
• Mercoledì 5 maggio 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mag 12 mer 2021 Seminar Fabio Peri, ''L'amor che move il sole e l'altre stelle''. Il cielo nella Divina Commedia,  12-05-2021, ore 12:15

• Seminar
• Fabio Peri
• Civico Planetario U. Hoepli di Milano
• ''L'amor che move il sole e l'altre stelle''. Il cielo nella Divina Commedia
• Mercoledì 12 maggio 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mag 19 mer 2021 Seminar Stefano Capolongo, Design and Health,  19-05-2021, ore 12:15

• Seminar
• Stefano Capolongo
• Politecnico di Milano
• Design and Health
• Mercoledì 19 maggio 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568

•  mag 26 mer 2021 Seminar Giuseppe Toscani, Meccanica statistica e fenomeni sociali,  26-05-2021, ore 12:15

• Seminar
• Giuseppe Toscani
• Università di Pavia
• Meccanica statistica e fenomeni sociali
• Mercoledì 26 maggio 2021 alle ore 12:15
• Aula B21 e online
• Politecnico di Milano, Dipartimento di Matematica edificio 14, via Giuseppe Ponzio 31/P, 20133 Milano - Telefono: +39 02 2399 4505 - Fax: +39 02 2399 4568