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[Indico] Kai Bergermann, Numerical linear algebra meets multiplex networks, 13/11/2025, 11:00 Europe/Rome
by fabio.durastante＠unipi.it 03 Nov '25

03 Nov '25

Title: Numerical linear algebra meets multiplex networks, Speaker(s): Kai Bergermann, Scuola Normale Superiore, Date and time: 13 Nov 2025, 11:00 (Europe/Rome), Lecture series: Seminar on Numerical Analysis, Venue: Department of Mathematics (Sala Riunioni). You can access the full event here: https://events.dm.unipi.it/e/329 Abstract -------- Multiplex networks are used to model complex systems from myriad applications. They generalize classical complex networks by recording different types of relationships, different interactions, or changing interactions over time between the same entities in different layers. They possess natural linear algebraic representations in terms of structured matrices, which makes efficient numerical linear algebra techniques a valuable tool for their analysis. In this talk, I will present contributions to multiplex network analysis relying on matrix function approximation and nonlinear spectral methods. I will discuss centrality measures, the solution of stiff systems of non-linear differential equations with exponential Runge--Kutta integrators, un- and semi-supervised community detection, and core-periphery detection. All presented methods have a linear runtime scaling, which allows the treatment of large-scale multiplex networks and numerical experiments for all considered problems will be presented. -- Indico :: Email Notifier https://events.dm.unipi.it/e/329

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Colloquium Daniela Calvetti
by Silvia Gazzola 20 Oct '25

20 Oct '25

Cari tutte e tutti, Vi scrivo per segnalarvi che, la prossima settimana, Daniela Calvetti<https://mathstats.case.edu/faculty/daniela-calvetti/> sarà in visita presso il nostro dipartimento. In particolare, lunedì 27 ottobre, alle ore 16, presso l'Aula Magna del Dipartimento di Matematica, terrà un colloquium dal titolo: `Linear algebra joins probability in the search for sparse and group sparse solutions with few data’. Trovate ulteriori dettagli al link: https://www.dm.unipi.it/en/seminar/?id=68f20c6cdefecee83efcca3e Fatemi pur anche sapere se desiderate interagire con Daniela Calvetti intanto che si trova a Pisa. Cordiali saluti, Silvia ============= Dr Silvia Gazzola Dipartimento di Matematica Università di Pisa https://sites.google.com/view/silviaspersonalwebpage/silvias-homepage ---------------------------------------------------------------------------------------------------------------------------------------------------------- You may receive this email outside my normal working hours — no response is expected outside your working hours ----------------------------------------------------------------------------------------------------------------------------------------------------------

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Seminario Fabio Credali - 25 Settembre 2025 - ore 12.00
by Luca Heltai 17 Sep '25

17 Sep '25

Car* tutt*, vi scrivo per segnalare un seminario che si terrà il 25 Settembre alle ore 12.00 in Sala riunioni presso il dipartimento di Matematica: Speaker: Dr. Fabio Credali, King Abdullah University of Science and Technology - KAUST Title: Advances on the finite element discretization of fluid-structure interaction problems Abstract: We review the main features of an unfitted finite element method for fluid-structure interaction problems based on a distributed Lagrange multiplier in the spirit of the fictitious domain approach. A coupling term describes the interaction between fluid and solid and it involves functions defined over two distinct non-matching grids, thus its evaluation is not trivial. We study the effect of exact and inexact integration by presenting quadrature estimates supported by numerical results. Moreover, we show that our method is stable even in presence of small cut cells and we provide an upper bound for the condition number. Finally, we outline the mass conservation properties of the proposed approach in the case of popular conforming finite element spaces. This work is a collaborative effort with Daniele Boffi, Lucia Gastaldi and Najwa Alshehri.

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Convegno al Centro De Giorgi: Morphogenesis and morphing, 200 years after Gauss
by Luca Heltai 15 Sep '25

15 Sep '25

Cari tutti, vi giro le informazioni su un convegno molto interessante giratemi da Antonio De Simone. La deadline per la registrazione è oggi... Cordialmente, Luca. > Begin forwarded message: > > From: Antonio De Simone <antonio.desimone(a)santannapisa.it> > Subject: [Junk released by User action] Convegno al Centro De Giorgi: Morphogenesis and morphing, 200 years after Gauss > Date: 10 September 2025 at 12:53:19 CEST > To: Alessandro Tognetti <alessandro.tognetti(a)unipi.it>, Roberto Paroni <rob.paroni(a)gmail.com>, Simone Camarri <simone.camarri(a)unipi.it>, "luca.heltai(a)unipi.it" <luca.heltai(a)unipi.it> > > Cari Roberto, Alessandro, Simone, Luca, > > il 20-24 ottobre prossimi organizzo un convegno internazionale al Centro De Giorgi della Scuola Normale Superiore, insieme ai matematici: > > https://indico.sns.it/event/122/ > https://indico.sns.it/event/122/ > > Sarà un convegno di alto livello, molto interdisciplinare e penso che potrebbe essere interessante per molti ricercatori e studenti a UniPI. > Posso chiedervi la cortesia di diffondere questa informazione attraverso i canali della vostra università e dei vostri dipartimenti? > Occorre registrarsi alla pagina web qui sotto: > > https://indico.sns.it/event/122/registrations/69/ > > Ovviamente siete invitantissimi a partecipare. > Grazie mille e cari saluti, > Antonio > > *** English Version*** > International worship at Centro De Giorgi, Pisa > 20-24 October 2025 > Morphogenesis and morphing, 200 years after Gauss: > > On October 20-24 there will be an interesting and high level international workshop at Centro De Giorgi (Scuola Normale Superiore, Pisa) entitled: > Morphogenesis and morphing, 200 years after Gauss: > > https://indico.sns.it/event/122/ > > Registration is required, via the following webpage: > > https://indico.sns.it/event/122/registrations/69/ > > Thank you and best wishes, > Antonio DeSimone > ****

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posizione dottorato Aalto university
by Federico Poloni 01 Jul '25

01 Jul '25

Cari tutti, Vanni Noferini mi segnala questa posizione di dottorato su “Matrix nearness problems via Riemannian optimisation’’: https://www.aalto.fi/en/open-positions/doctoral-candidate-in-applied-mathem… Inoltro qui, anche se è in concorrenza con le nostre a Pisa in Matematica e HPSC ( https://www.dm.unipi.it/bandi-di-concorso-per-lammissione-ai-dottorati-di-r… ). Un caro saluto, Federico -- --Federico Poloni Dipartimento di Informatica, Università di Pisa https://www.di.unipi.it/~fpoloni/ tel:+39-050-2213143

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Nello Cristianini a Pisa
by Gianna M. Del Corso 20 May '25

20 May '25

Cari colleghi, Giovedì 22/5 alle 11:00 nell’aula magna dell’ex facoltà di Scienze, Nello Cristianini, professore di intelligenza artificiale all’ Università di Bath terrà una presentazione del suo libro "Machina Sapiens <https://www.mulino.it/isbn/9788815384461>” discutendo dei rischi e delle implicazioni dell'AI generativa. Sarà un'ottima occasione per approfondire temi di grande attualità nel nostro campo con uno dei principali esperti dell'argomento, che li presenterà in modo accessibile. Vi incoraggio a partecipare e a contribuire alla discussione, invitando anche gli studenti del nostro corso di laurea. Cordiali saluti, Gianna @@@@@@@@@@@@@@@@@ Gianna M. Del Corso, PhD Dipartimento di Informatica, Università di Pisa Largo Pontecorvo, 3 56127 Pisa, Italy ph. +39-050-2213118 @@@@@@@@@@@@@@@@@

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[Indico] Federica Mugnaioni, Optimal and Scalable Augmented Lagrangian preconditioners for Fictitious Domain problems, 13/05/2025, 11:00 Europe/Rome
by fabio.durastante＠unipi.it 12 May '25

12 May '25

Title: Optimal and Scalable Augmented Lagrangian preconditioners for Fictitious Domain problems, Speaker(s): Federica Mugnaioni, Scuola Normale Superiore, Date and time: 13 May 2025, 11:00 (Europe/Rome), Lecture series: Seminar on Numerical Analysis, Venue: Dipartimento di Matematica (Saletta Riunioni). You can access the full event here: https://events.dm.unipi.it/e/321 Abstract -------- One of the major drawbacks of using Fictitious Domain methods is the computational demands of solving the associated large-scale linear systems, both in terms of time and memory. To address this issue, we propose two augmented Lagrangian-based preconditioners for efficiently solving linear systems of equations with a block two-by-two and three-by-three structure arising from fictitious domain problems and from finite element discretizations of immersed boundary methods. We consider two relevant examples to illustrate the performance of these preconditioners when used in conjunction with flexible GMRES: the Poisson and the Stokes fictitious domain problems. We provide a detailed spectral analysis, deriving lower and upper bounds for the eigenvalues of the preconditioned matrix and showing their independence with respect to discretization parameters. Furthermore, we discuss the eigenvalue distribution when inexact versions of the preconditioners are employed. We show the effectiveness of the proposed approach and the robustness of our preconditioning strategies through extensive numerical tests in both two and three dimensions, using different immersed geometries.M. Benzi, M. Feder, L. Heltai and F. Mugnaioni. Optimal and Scalable Augmented Lagrangian preconditioners for Fictitious Domain problems. arXiv:2504.11339, 2025 Note ---- A reminder of tomorrow's seminar. -- Indico :: Email Notifier https://events.dm.unipi.it/e/321

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[Indico] Federica Mugnaioni, Optimal and Scalable Augmented Lagrangian preconditioners for Fictitious Domain problems, 13/05/2025, 11:00 Europe/Rome
by fabio.durastante＠unipi.it 28 Apr '25

28 Apr '25

Title: Optimal and Scalable Augmented Lagrangian preconditioners for Fictitious Domain problems, Speaker(s): Federica Mugnaioni, Scuola Normale Superiore, Date and time: 13 May 2025, 11:00 (Europe/Rome), Lecture series: Seminar on Numerical Analysis, Venue: Dipartimento di Matematica (Saletta Riunioni). You can access the full event here: https://events.dm.unipi.it/e/321 Abstract -------- One of the major drawbacks of using Fictitious Domain methods is the computational demands of solving the associated large-scale linear systems, both in terms of time and memory. To address this issue, we propose two augmented Lagrangian-based preconditioners for efficiently solving linear systems of equations with a block two-by-two and three-by-three structure arising from fictitious domain problems and from finite element discretizations of immersed boundary methods. We consider two relevant examples to illustrate the performance of these preconditioners when used in conjunction with flexible GMRES: the Poisson and the Stokes fictitious domain problems. We provide a detailed spectral analysis, deriving lower and upper bounds for the eigenvalues of the preconditioned matrix and showing their independence with respect to discretization parameters. Furthermore, we discuss the eigenvalue distribution when inexact versions of the preconditioners are employed. We show the effectiveness of the proposed approach and the robustness of our preconditioning strategies through extensive numerical tests in both two and three dimensions, using different immersed geometries.M. Benzi, M. Feder, L. Heltai and F. Mugnaioni. Optimal and Scalable Augmented Lagrangian preconditioners for Fictitious Domain problems. arXiv:2504.11339, 2025 -- Indico :: Email Notifier https://events.dm.unipi.it/e/321

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Colloquium 17 aprile ore 16.00
by Stefano Massei 15 Apr '25

15 Apr '25

Cari tutti, a nome della Commissione Colloquia di Dipartimento, vi ricordo che giovedì 17 aprile alle 16.00 in AULA MAGNA Virginie Ehrlacher<https://team.inria.fr/matherials/team-members/virginie-ehrlacher-galland/> (Ecole des Ponts ParisTech) terrà un <https://www.dm.unipi.it/en/seminar/?id=67a64aff762f5b32f7b4dfd3> colloquium<https://www.dm.unipi.it/en/seminar/?id=67a64aff762f5b32f7b4dfd3> sul tema: “A sparse approximation of the Lieb functional with moment constraints”. Cordiali saluti, Stefano Massei

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Next NUMPI seminar: set the date
by Fabio Durastante 15 Apr '25

15 Apr '25

Good morning, We would like to fix the date for the next NUMPI seminar in May. It will be a seminar held by Federica Mugnaioni (Ph.D. Scuola Normale Superiore) on the topic of preconditioners for discretization of fictitious domain problems. Please reply with your availability for the days of May 12/13 and we will try to organize it at a time convenient for most of us: https://date.dm.unipi.it/Vh6AwjL3MKGWBESp Best, Fabio

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