December 2024 - Geometria_Pisa - Mailing list — Dipartimento di Matematica, UniPI

I: Spring school on singularities - Nantes - 22nd-25th April 2025
by Paolo Lisca 18 Dec '24

18 Dec '24

Inoltro annuncio di scuola primaverile. Paolo Lisca ________________________________ Da: Fabio Gironella <fabio.gironella(a)univ-nantes.fr> Inviato: martedì 17 dicembre 2024 14:03 A: orga-school-sing(a)univ-nantes.fr Oggetto: Spring school on singularities - Nantes - 22nd-25th April 2025 Dear friends and colleagues, We are pleased to announce a spring school at Nantes Université, which will take place from the 22nd to the 25th of April 2025. The school is part of the thematic semester 2025 Singularities<https://www.lebesgue.fr/fr/semestre2025>, organised by the Centre Henri Lebesgue<https://www.lebesgue.fr/fr>. Our school, aimed at Master and PhD students, will focus on singularities in low-dimensional and symplectic topology. It will mainly revolve around two mini-courses, of four hours plus an exercise session each. The two courses will be given by Anne Pichon<https://www.i2m.univ-amu.fr/perso/anne.pichon/> (Aix-Marseille Université), on the low-dimensional side, and by Jonathan Evans<https://jde27.uk/> (Lancaster University), on the symplectic side. Beside the two mini-courses, there will be a session for short talks. We invite participants who would like to talk about their research to submit a title and an abstract. The schedule will be rather light, so enough time will be left for participants to discuss together and discover each other's research interests. Registration is open until February 23rd 2024. We will be able to provide accommodation (in twin bedrooms) for a limited number of participants. You can register and apply for funding here<https://www.lebesgue.fr/fr/lowdim-symp2025/inscription>. More information on the school can be found at these pages: https://fabiogironella.com/events/25_04_spring_school_nantes_singularities/ and https://www.lebesgue.fr/en/lowdim-symp2025 Please forward this announcement to colleagues/students who might be interested in attending the spring school. Best regards, Fabio Gironella, Marco Golla and Stéphane Guillermou (the organisers)

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Seminario Baby Geometri 17/12
by Giovanni Framba 12 Dec '24

12 Dec '24

Carə tuttə, Vi invitiamo al seminario dei Baby Geometri della prossima settimana: Martedì 17 Dicembre 2024, alle ore 11:30 Presso l’Aula Seminari del Dipartimento di Matematica Giacomo Bascapè (Université du Québec à Montréal) terrà un seminario dal titolo: SU(2)-representations of 3-manifolds: a brave new world di cui riportiamo l'abstract: In this talk, we will explore the world of SU(2) representations applied to 3-manifolds. First, we will introduce the importance of SU(2)-representations as an invariant of non-triviality. Then, we will describe this theory's relations to the L-space conjecture, particularly to instanton Floer homology. Finally, we will apply some of these techniques to the case of graph manifolds with small order. Vi ricordiamo che potrete trovare informazioni sui prossimi seminari sul nostro sito https://sites.google.com/view/babygeometri. Tutte le persone interessate sono invitate a partecipare. A presto, Elena Bogliolo Pietro Capovilla Alessio Di Prisa Giovanni Framba Ervin Hadžiosmanović

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Seminario di Geometria 10 Dicembre - Enrico Trebeschi
by Carlo Collari 06 Dec '24

06 Dec '24

Buongiorno, Ricordo a tutti gli interessati che il prossimo (e ultimo per questo semestre) seminario di geometria sarà tenuto da Enrico Trebeschi e si terrà Martedì 10 Dicembre alle ore 14:30 presso l'aula Riunioni. Per gli interessati ad andare a pranzo con lo speaker, l'appuntamento è in atrio alle 13:00. Allego titolo e abstract: Titolo: Rigidity Results for Maximal Submanifolds in Pseudo-Hyperbolic Space Abstact: Maximal submanifolds are the generalization in pseudo-Riemannian geometry of minimal surfaces. Their study in pseudo-hyperbolic space, which is the generalization of hyperbolic space in mixed signature, is motivated by several factors ranging from differential geometry, relativistic physics, and, in recent years, geometric topology. A classical problem in the study of minimal submanifolds of the unit sphere is to find a universal upper bound for the norm of the second fundamental form, that is, to estimate their extrinsic curvature. In this seminar, I will discuss a recent work in collaboration with Alex Moriani (Université Côte d'Azur), in which we provide a sharp bound on the norm of the second fundamental form for maximal submanifolds in pseudo-hyperbolic space. In particular, this bound is rigid, meaning it is achieved identically, and we are able to explicitly classify the submanifolds that achieve it. Gauss equation translates the estimate on the extrinsic curvature in trems of the intrinsic curvature, allowing us to prove that the scalar curvature of a maximal submanifold is non-positive and to classify those with vanishing scalar curvature. In the Lorentzian case, we are able to provide a rigid estimate on the Ricci curvature as well. If I have time, I would like to discuss the implications of this work in the context of Teichmüller theory of higher rank and dimension, namely the study of connected components of Hom(π1(M), G) containing only faithful and discrete representations, where M is a closed manifold of dimension n>2 and G is a semi-simple Lie group of rank >1. A presto, Carlo e Filippo

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Seminario Baby Geometri 10/12
by Giovanni Framba 06 Dec '24

06 Dec '24

Carə tuttə, Vi invitiamo al seminario dei Baby Geometri della prossima settimana: Martedì 03 Dicembre 2024, alle ore 11:30 Presso l’Aula Seminari del Dipartimento di Matematica Luigi Marigliano(Università di Pisa) terrà un seminario dal titolo: Riemannian holonomy classification di cui riportiamo l'abstract: Holonomy was introduced by Élie Cartan in 1926 and has since then provided a way to apply the machinery of Lie groups representation to study Riemannian manifolds. In this talk we will start by introducing holonomy in vector and principal bundles, providing some examples, to arrive at the main result obtained by Berger for the classification of the holonomy of Riemannian manifolds. Vi ricordiamo che potrete trovare informazioni sui prossimi seminari sul nostro sito https://sites.google.com/view/babygeometri. Tutte le persone interessate sono invitate a partecipare. A presto, Elena Bogliolo Pietro Capovilla Alessio Di Prisa Giovanni Framba Ervin Hadžiosmanović

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Seminario di Geometria 3 Dicembre 2024 - Andrea Sambusetti
by Carlo Collari 02 Dec '24

02 Dec '24

Buongiorno, Ricordo a tutti gli interessati che il prossimo seminario di geometria sarà tenuto da Andrea Sambusetti e si terrà domani Martedì 3 Dicembre alle ore 14:30 presso l'aula Riunioni. Per gli interessati ad andare a pranzo con lo speaker, l'appuntamento è in atrio alle 13:00. Allego titolo e abstract: Titolo: Two rigidity theorems for CAT(0)-spaces (via convergence theory) Abstact: I will present two rigidity results about CAT(0)-spaces. The first one concerns the isolation of flat spaces among (geodesically complete) CAT(0)-spaces admitting cocompact lattices, provided that the codiameter is uniformily bounded. The second one is an entropy-pinching theorem saying that if a uniformly packed and uniformly cocompact CAT(0)-space has entropy small enough, then it is flat. Both results stem from a careful study of the theory of (equivariant) Gromov-Hausdorff convergence of lattices of CAT(0)-spaces and of their possible degenerations, whose main lines I will try to explain. A presto, Carlo e Filippo

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