- Geometria_Pisa - Mailing list — Dipartimento di Matematica, UniPI

Assegno
by Bruno Martelli 12 Sep '24

12 Sep '24

Buongiorno, È uscito il bando per l'assegno in algebra e geometria presso il nostro dipartimento: https://bandi.unipi.it/public/Bandi/Detail/86b7b083-0de4-4d15-b9b2-ca1002a1… . La scadenza per la presentazione delle domande è *il 10 ottobre 2024 alle ore 13.00*.

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Seminario di geometria 12/9
by Diego Conti 08 Sep '24

08 Sep '24

Buonasera, segnalo che giovedì 12 settembre alle 14.30 in aula seminari Federico Alberto Rossi (Università di Perugia) terrà un seminario dal titolo *Constructing Indefinite Einstein Solvmanifolds Beyond Nilsolitons* di cui riporto l'abstract: In the Riemannian setting, the theory of Einstein solvmanifolds is well established and extensively understood. In this seminar, we will initially review the Riemannian case, providing a foundation for our subsequent exploration of the indefinite setting. Then, we will switch to indefinite metrics, highlighting with examples the differences with the Riemannian case. However, we will describe analogous techniques for constructing pseudo-Riemannian Einstein solvmanifolds using indefinite nilsolitons, emphasizing the role of pseudo-Iwasawa decomposition and nice nilpotent Lie algebras. Next, we will introduce two distinct methods for constructing Einstein solvmanifolds, which are not based on nilsolitons and are unique to the indefinite setting. The first approach involves contact symplectic reduction, a technique characteristic of pseudo-Sasaki geometry. The second, a more recent development, is based on solving the generalized nilsoliton equation and presents a new methodological framework. Both methods produce examples of Einstein solvmanifolds that are not isometric to any of the pseudo-Iwasawa type. Time permitting, we will also discuss the interplay between Einstein solvmanifolds and related geometric structures, such as Sasaki, pseudo-Kähler, and para-Kähler geometries. This presentation is based on joint work with D. Conti and R. Segnan Dalmasso. Per chi fosse interessato ad andare a pranzo con lo speaker ci troveremo alle 13 in atrio. A presto, Diego

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Fwd: REMINDER - Bandi di concorso Assegni di Ricerca Post dottorali INdAM
by Bruno Martelli 05 Sep '24

05 Sep '24

---------- Forwarded message --------- Da: ISTITUTO NAZIONALE DI ALTA MATEMATICA <indam(a)altamatematica.it> Date: Gio 5 Set 2024, 11:30 Subject: REMINDER - Bandi di concorso Assegni di Ricerca Post dottorali INdAM To: gnampa-aderenti(a)altamatematica.it <gnampa-aderenti(a)altamatematica.it>, gnsaga-aderenti(a)altamatematica.it <gnsaga-aderenti(a)altamatematica.it>, gnfm-aderenti(a)altamatematica.it <gnfm-aderenti(a)altamatematica.it>, gncs-aderenti(a)altamatematica.it <gncs-aderenti(a)altamatematica.it> A tutti gli aderenti, si ricorda che sono disponibili due *Bandi di concorso, *le cui domande dovranno essere presentate entro il *20 settembre 2024* esclusivamente mediante apposita modulistica elettronica predisposta all'interno del sito WEB dell'INdAM: https://www.altamatematica.it/bandi/: *1) Bando di concorso a n. 6 assegni post dottorali di collaborazione ad attività di* *ricerca per l'a.a. 2024-2025 *pubblicato sulla Gazzetta Ufficiale 4a Serie Speciale – Concorsi ed Esami n. 62 del 02 agosto 2024. Gli assegni hanno una durata *annuale*. All’assegnista sarà corrisposta una somma pari a *€ 36.500 lordi annui*. Inoltre, l’assegnista disporrà di un fondo di ricerca pari a *€* *5.000,00 netti annui*. Al concorso possono partecipare giovani attivi nella ricerca matematica che abbiano conseguito il titolo di dottore di ricerca o titolo equipollente o un titolo di studio rilasciato da un’Università straniera comparabile al titolo di dottore di ricerca dopo il 1 giugno 2023 o che lo conseguono entro il 20 settembre 2024. *2) Bando di concorso a **n. 2 assegni post dottorali di collaborazione ad attività di* *ricerca **“Ing. Giorgio Schirillo” **per l'a.a. 2024-2025 *pubblicato sulla Gazzetta Ufficiale 4a Serie Speciale – Concorsi ed Esami n. 62 del 02 agosto 2024. Gli assegni hanno una durata *annuale*. All’assegnista sarà corrisposta una somma pari a *€ 24.000 lordi annui*. Al concorso possono partecipare giovani attivi nella ricerca matematica che abbiano conseguito il titolo di dottore di ricerca o titolo equipollente o un titolo di studio rilasciato da un’Università straniera comparabile al titolo di dottore di ricerca dopo il 20 settembre 2019 o che lo conseguono entro il 20 settembre 2024. Cordiali saluti, Segreteria INdAM [image: image.png]

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Re: Seminario Hideki Miyachi, venerdì 19 luglio, 11h
by Fabrizio Bianchi 19 Jul '24

19 Jul '24

Buongiorno, Ricordo, per chi volesse partecipare, che il seminario di Hideki Miyachi inizia tra poco in sala seminari. Cordiali saluti, Fabrizio Il lun 15 lug 2024, 18:04 Fabrizio Bianchi <fabrizio.bianchi(a)unipi.it> ha scritto: > Buongiorno, > > scrivo per avvisare che venerdì 19 alle 11, in aula seminari, ci sarà un > seminario di Hideki Miyachi (Kanazawa University, Japan), di cui riporto > sotto titolo e abstract. > > Hideki è ospite del Centro de Giorgi dal 15 al 26 luglio, per un Research > in Pairs. > > In seguito al seminario, andremo a pranzo con l'ospite (probabilmente al > Quore). Vi chiedo di farmi sapere entro mercoledì se pensate di esserci per > il pranzo, così da poter prenotare. > > Grazie in anticipo, e a presto, > Fabrizio > > > ------- > Title : Toward Complex Geometry of Teichmueller space > Abstract: > The Teichmueller space of Riemann surfaces of genus g is a deformation > space of marked Riemann surfaces of genus g. It is the orbifold universal > covering space over Riemann's moduli space of Riemann surfaces, with the > Deck transformation group being a quotient group of the mapping class > group. TheTeichmueller space has a natural complex structure and is > considered the universal space of holomorphic families of Riemann surfaces. > It also has a natural Finsler metric on the tangent bundle called the > Teichmueller metric, which coincides with the Kobayashi metric. > Furthermore, the Teichmueller space of tori is canonically identified with > the upper-half space via the generators of lattices, and the Teichmueller > metric coincides with the Poincaré metric of curvature -4. In this talk, I > will discuss my recent progress on the complex geometry of the Teichmueller > space. We will begin with the Teichmueller space of tori to discuss the > model case and present results including > > • the characterization of the PluriGreen function and the Poisson > integral formula; and > • the infinitesimal properties of the Teichmueller metric. > > If time permits, I would also like to address ongoing problems and > conjectures. > —— > > > -- > Fabrizio Bianchi > Dipartimento di Matematica > Largo Bruno Pontecorvo 5 > 56127 Pisa, Italy > https://people.cs.dm.unipi.it/bianchi/ > >

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Seminario Hideki Miyachi, venerdì 19 luglio, 11h
by Fabrizio Bianchi 16 Jul '24

16 Jul '24

Buongiorno, scrivo per avvisare che venerdì 19 alle 11, in aula seminari, ci sarà un seminario di Hideki Miyachi (Kanazawa University, Japan), di cui riporto sotto titolo e abstract. Hideki è ospite del Centro de Giorgi dal 15 al 26 luglio, per un Research in Pairs. In seguito al seminario, andremo a pranzo con l'ospite (probabilmente al Quore). Vi chiedo di farmi sapere entro mercoledì se pensate di esserci per il pranzo, così da poter prenotare. Grazie in anticipo, e a presto, Fabrizio ------- Title : Toward Complex Geometry of Teichmueller space Abstract: The Teichmueller space of Riemann surfaces of genus g is a deformation space of marked Riemann surfaces of genus g. It is the orbifold universal covering space over Riemann's moduli space of Riemann surfaces, with the Deck transformation group being a quotient group of the mapping class group. TheTeichmueller space has a natural complex structure and is considered the universal space of holomorphic families of Riemann surfaces. It also has a natural Finsler metric on the tangent bundle called the Teichmueller metric, which coincides with the Kobayashi metric. Furthermore, the Teichmueller space of tori is canonically identified with the upper-half space via the generators of lattices, and the Teichmueller metric coincides with the Poincaré metric of curvature -4. In this talk, I will discuss my recent progress on the complex geometry of the Teichmueller space. We will begin with the Teichmueller space of tori to discuss the model case and present results including • the characterization of the PluriGreen function and the Poisson integral formula; and • the infinitesimal properties of the Teichmueller metric. If time permits, I would also like to address ongoing problems and conjectures. —— -- Fabrizio Bianchi Dipartimento di Matematica Largo Bruno Pontecorvo 5 56127 Pisa, Italy https://people.cs.dm.unipi.it/bianchi/

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Workshop announcement
by Carlo Collari 03 Jul '24

03 Jul '24

Dear All, This is to announce the workshop Combinatorial Algebraic Topology, and Applications II (CATA II) that will be held at Centro De Giorgi in Pisa (IT) from the 1st to the 4th of October 2024. Registration is available at the webpage (http://www.crm.sns.it/event/532/) Registration is free, although mandatory, due to restrictions on the number of participants. A preliminary list of speakers includes: Filippo Callegaro (Università di Pisa) Paola Cristofori (Università di Modena e Reggio Emilia) Brent Everitt (University of York) Dejan Govc (University of Ljubljana) Claudia Landi (Università di Modena e Reggio Emilia) Ran Levi* (University of Aberdeen) Martino Lupini (Università di Bologna) Giuliamaria Menara (Università degli Studi di Trieste) Marija Jelic Milutinovic (University of Belgrade) Christine Vespa (Université Aix-Marseille) *to be confirmed Limited funding might be available to junior participants. In case of interest, please contact Luigi Caputi (luigi.caputi(a)unito.it<mailto:luigi.caputi@unito.it>) or Carlo Collari (carlo.collari(a)dm.unipi.it<mailto:carlo.collari@dm.unipi.it>). The workshop includes some sessions of contributed talks. Those interested in applying should send an email to crm(a)sns.it<mailto:crm@sns.it> (with the organisers in CC), including title and abstract (and financial support request, if any), for the evaluation by the Scientific Committee. The deadline for both funding and contributed talks is the 9th of August 2024. Looking forward to seeing you in Pisa. The organizers, Luigi Caputi and Carlo Collari

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Re: Seminario geometria domani
by Bruno Martelli 20 Jun '24

20 Jun '24

Per chi fosse interessato a pranzare con lo speaker, ci troviamo nell'atrio alle 12.30 Bruno Il Mer 19 Giu 2024, 10:39 Bruno Martelli <bruno.martelli(a)unipi.it> ha scritto: > Buondì, > Con colpevole ritardo vi annuncio il seminario di geometria e topologia di > domani. > A presto, > Bruno > > Orario: Giovedì 20 giugno, ore 14.30, aula seminari. > Speaker: Sam Fisher (Oxford) > Title: Maps to the circle, the integers, and L2-Betti numbers > > Abstract: Determining conditions implying that a manifold fibers over the > circle is an old and interesting problem. One of the most celebrated > results in this direction is Agol's theorem, which states that every > hyperbolic 3-manifold has a finite cover that fibers over the circle. In > higher dimensions, much less is known. Recently, > Italiano--Martelli--Migliorini gave the first example of a (cusped) > hyperbolic 5-manifold fibering over the circle, answering open questions in > topology and geometric group theory. Hyperbolic 3-manifolds and the IMM > example are examples of hyperbolic manifolds whose fundamental groups act > geometrically on CAT(0) cube complexes and consequentially have RFRS > fundamental group. In this talk, we will discuss an algebraic version of > the fibering problem: a group algebraically fibers if it maps onto the > integers with finitely generated kernel. In the class of RFRS groups, we > will see that finiteness properties of the kernel are controlled by > vanishing of L2-invariants. We will also discuss applications of these > results to high-dimensional hyperbolic manifolds >

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Seminario geometria domani
by Bruno Martelli 19 Jun '24

19 Jun '24

Buondì, Con colpevole ritardo vi annuncio il seminario di geometria e topologia di domani. A presto, Bruno Orario: Giovedì 20 giugno, ore 14.30, aula seminari. Speaker: Sam Fisher (Oxford) Title: Maps to the circle, the integers, and L2-Betti numbers Abstract: Determining conditions implying that a manifold fibers over the circle is an old and interesting problem. One of the most celebrated results in this direction is Agol's theorem, which states that every hyperbolic 3-manifold has a finite cover that fibers over the circle. In higher dimensions, much less is known. Recently, Italiano--Martelli--Migliorini gave the first example of a (cusped) hyperbolic 5-manifold fibering over the circle, answering open questions in topology and geometric group theory. Hyperbolic 3-manifolds and the IMM example are examples of hyperbolic manifolds whose fundamental groups act geometrically on CAT(0) cube complexes and consequentially have RFRS fundamental group. In this talk, we will discuss an algebraic version of the fibering problem: a group algebraically fibers if it maps onto the integers with finitely generated kernel. In the class of RFRS groups, we will see that finiteness properties of the kernel are controlled by vanishing of L2-invariants. We will also discuss applications of these results to high-dimensional hyperbolic manifolds

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Conferenza Nantes in topologia in bassa dimensione
by Bruno Martelli 10 Jun '24

10 Jun '24

Buondì, Inoltro annuncio di conferenza, attenzione perché le iscrizioni scadono in questi giorni. Bruno ----- Chers collègues, Vous êtes cordialement invité(e)s aux prochaines journées de topologie de basse dimension du Réseau Thématique RTop "Topologie algébrique et géométrique" qui auront lieu à Nantes du 26 au 30 aout prochain. https://www.math.sciences.univ-nantes.fr/~golla/docs/conferences/nantes-tre… Nous aurons le plaisir d'y écouter deux mini-cours : Marco MARENGON (Alfreìd Reìnyi Institute of Mathematics), Laura STARKSON (UC Davis), ainsi que des exposés pléniers de : Cristina ANGHEL-PALMER (University of Leeds), Roger CASALS (UC Davis), Filip MISEV (Universität Regensburg), Hoel QUEFFELEC (Université de Montpellier), Les inscriptions sont ouvertes ici : https://www.math.sciences.univ-nantes.fr/journees-de-basse-dimension/ N'hésitez pas à faire des propositions d'exposés pour enrichir le programme de la semaine et n'hésitez pas à nous contacter si besoin est. Le nombre de places étant limité, nous confirmerons les inscriptions ultérieurement. En espérant vous y voir nombreux ! Les organisateurs (M. Golla, E. Wagner) (English version) Dear colleagues, We are pleased to announce that the next Low-dimensional meeting of the Réseau Thématique RTop "Topologie algébrique et géométrique" will take place in Nantes on August 26th-30th (2024). We will have the pleasure to listen to two mini-courses by: Marco MARENGON (Alfreìd Reìnyi Institute of Mathematics), Laura STARKSON (UC Davis), as well as to plenary talks by: Cristina ANGHEL-PALMER (University of Leeds), Roger CASALS (UC Davis), Filip MISEV (Universität Regensburg), Hoel QUEFFELEC (Université de Montpellier), Registration is open here: https://www.math.sciences.univ-nantes.fr/journees-de-basse-dimension/ Due to the limited number of places, registration will be confirmed later on. Do not hesitate to suggest contributed talks to enrich the program and do not hesitate to contact us if you have any questions. Looking forward to seeing you in Nantes, The organizers (M. Golla, E. Wagner)

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seminario Romeo Segnan Dalmasso
by Diego Conti 21 May '24

21 May '24

Buongiorno, segnalo che giovedì 23 maggio alle 14.30 in aula seminari Romeo Segnan Dalmasso (Università di Milano Bicocca) terrà un seminario dal titolo *Harmful structures and Killing spinors* di cui riporto l'abstract: The existence of Killing spinors on a given manifold imposes strict conditions on its geometry. In the Riemannian setting in particular, this implies, for example, that the metric is Einstein. In the pseudo-Riemannian setting, the situation is less studied, nor as strict, for instance the metric need not be Einstein. In this talk, after an introduction to the language of spinors and some history concerning their study, I will present a new result concerning the existence of a Killing spinor on a pseudo-Riemannian manifold (Z, h). I will show that the existence on (Z, h) implies the existence of a pair of spinors (\psi, \phi) in the spinor bundle of an embedded (non-degenerate) hypersurface (M, g) satisfying a coupled PDE system involving the Weingarten operator of the embedding A, which will be called real or imaginary weakly /harmful structure/, depending on the signature of the normal vector-field to (M, g). The embedding process will require an additional technical condition, namely d tr A+\delta A = 0, and the assumption that the metric and the Weingarten operator are real analytic tensors. Some comments will be given on the special case of Lorentzian signature. Finally, I will present some work in progress regarding a (partial) classification in low dimension of harmful structures on homogeneous manifolds and the resulting cohomogeneity-one embeddings. This talk is based on a joint work with D. Conti and F.A. Rossi. A presto Diego

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