May 2018 - Geometria_Pisa - Mailing list — Dipartimento di Matematica, UniPI

Fwd: [Algtop] due seminari giovedì 31
by Bruno Martelli 30 May '18

30 May '18

Buongiorno, Segnalo due seminari di geometria / algebra per domani pomeriggio. A presto, Bruno ====================================== giovedi` 31 maggio ore 15 aula seminari Luca Battistella Relative quasimaps and quasimap quantum Lefschetz Quasimaps provide a compactification of the space of maps from smooth curves to a GIT quotient; Ciocan-Fontanine and Kim used them to prove beautiful wall-crossing formulae, comparing the resulting invariants with ordinary Gromov-Witten ones. In joint work with Navid Nabijou, we introduce the notion of genus zero relative quasimaps to a toric target X with respect to a smooth (but not necessarily toric) hyperplane section Y, extending work of Gathmann to this setting. Increasing the tangency requirement gives us smaller and smaller moduli spaces; their virtual classes are related by a simple recursion formula. Gathmann's inductive algorithm allows us to compute restricted invariants of Y from those of X. Under some positivity assumption, this can be made into a compact formula for generating series of quasimap invariants, which recovers a result of Ciocan-Fontanine and Kim. We are working towards an extension of this approach to reduced genus one invariants. giovedi` 31 maggio ore 16 aula seminari Giovanni Inchiostro Moduli of Weierstrass fibrations. We study the the moduli space of KSBA stable pairs (X,sS+\sum a_i F_i), consisting of a Weierstrass fibration X, its section S, and some fibers F_i. We find a compactification which is a DM stack, and we prove that there are wall-crossing morphisms when the weights s and a_i change. This recovers the work of Ascher and Bejleri in the case in which s=1 and the one of La Nave when s=1 and a_i=0. _______________________________________________ Algtop mailing list Algtop(a)fields.dm.unipi.it https://fields.dm.unipi.it/listinfo/algtop

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Ultimo seminario dei Baby Geometri
by Marco Moraschini 25 May '18

25 May '18

Cari tutti, vi segnalo l'ultima attività per il ciclo di seminari dei Baby Geometri di quest'anno: Lunedì 28 Maggio alle 16:30 presso l'Aula Magna del Dipartimento di Matematica Mauro Artigiani (Centro De Giorgi) terrà un seminario dal titolo: Dynamics on translation surfaces: a (very very very) short survey di cui riporto l'abstract: "Translation surfaces are surfaces which come naturally into play both from a dynamical motivation (billiards in polygons) and from a more algebro-geometrical point of view (they are related to the Teichmuller space). We will start with some examples, give some motivations about why one is interested in them and then focus more on the dynamical side. We will give a short survey of some more or less classical result from the very rich literature. Time permitting, we will also relate this to some Diophantine approximation." A seguire ci sarà un brindisi per sancire la fine del ciclo di seminari per quest'anno! Tutti gli interessati sono invitati a partecipare. Per saperne di più sui prossimi seminari scrivete a babygeometri(a)cs.dm.unipi.it <https://student-web1.dm.unipi.it/squirrelmail/src/compose.php?send_to=babyg…> o consultate la nostra pagina web: http://people.dm.unipi.it/babygeometri/ Saluti, Giulio Belletti, Edoardo Fossati e Marco Moraschini

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Seminario dei Baby Geometri
by Marco Moraschini 22 May '18

22 May '18

Cari tutti, vi segnalo questa attività per il ciclo di seminari dei Baby Geometri: Venerdì 25 Maggio alle 16:30 presso l'Aula Seminari del Dipartimento di Matematica Maylis Limouzineau (Università di Colonia) terrà un seminario dal titolo: Legendrian cobordisms di cui riporto l'abstract: Our framework here is low dimensional topology, and the main protagonists are Legendrian submanifolds, i.e. those which remains obediently tangent to the contact hyperplane distribution. We will see the subtleties brought by Legendrian knots in comparison with classical smooth knots, and understand the natural cobordism notion coming out, initiated by Arnol'd in the early 80's: "What is a Legendrian surface between two Legendrian knots?" There will be infinitely many trivial knots, some bow ties, one swallow tail... and a lot of drawings. Tutti gli interessati sono invitati a partecipare. Per saperne di più sui prossimi seminari scrivete a babygeometri(a)cs.dm.unipi.it <https://student-web1.dm.unipi.it/squirrelmail/src/compose.php?send_to=babyg…> o consultate la nostra pagina web: http://people.dm.unipi.it/babygeometri/ Saluti, Giulio Belletti, Edoardo Fossati e Marco Moraschini

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Research Felllow position in algebra and geometry in Pisa - Posto da ricercatore di tipo A in algebra e geometria a Pisa
by Bruno Martelli 17 May '18

17 May '18

Dear colleague, A Junior Research Fellow position (Ricercatore di Tipo A) is currently open in algebra or geometry at the Math Department in Pisa. Contract duration: 3 years Gross annual salary: € 34.898 Deadline for application: 04/06/2018, 1 p.m. Here is the link: https://www.unipi.it/ateneo/bandi/ricercat/ricercator/Procedura-2/index.htm I would be grateful if you could forward this information to any potentially interested candidate. Best wishes, Bruno Martelli

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Seminario geometria
by Bruno Martelli 15 May '18

15 May '18

Buongiorno, Siete invitati al seminario di geometria di domani (c'è purtroppo una sovrapposizione con un altro seminario in Normale di cui mi accorgo solo ora... ). A presto, Bruno Martelli 16-May-2018 - 15:30 Sala Seminari (Dip. Matematica) <http://www.dm.unipi.it/webnew/it/aula/sala-seminari-dip-matematica> Pretzel links, mutation, and the slice-ribbon conjecture <http://www.dm.unipi.it/webnew/it/seminari/pretzel-links-mutation-and-slice-…> Paolo Aceto We show that the mutant 2-component pretzel links P(p,q,-q,-p) and P(p,q,-p,-q) are not concordant for any distinct odd integers p and q greater than 1. As a corollary, we obtain a proof of the slice-ribbon conjecture for 4-stranded 2-component pretzel links. In order to distinguish mutant links up to concordance we consider 3-fold branched covers and use an obstruction based on Donaldson's diagonalization theorem. This is joint work with Min Hoon Kim, JungHwan Park and Arunima Ray.

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Seminario dei Baby Geometri
by Marco Moraschini 10 May '18

10 May '18

Cari tutti, vi segnalo questa attività per il ciclo di seminari dei Baby Geometri: Lunedì 14 Maggio alle 16:30 presso l'Aula Seminari del Dipartimento di Matematica Lorenzo Ruffoni (Università di Bologna) terrà un seminario dal titolo: Complex projective structures and Hilbert's XXI problem di cui riporto l'abstract: Complex projective structures are geometric structures locally modeled on the geometry of the Riemann sphere with its group of Möbius transformations PSL(2,C). As this space appears as a natural boundary at infinity for the hyperbolic space, a typical feature of these structures is the interplay between complex analysis and hyperbolic geometry, which gives rise to a rich deformation theory. After reviewing some of the main properties of their deformation space, we will discuss how the study of complex projective structures can provide solutions to Hilbert's XXI problem about monodromy groups of certain classes of ODEs on Riemann surfaces. Tutti gli interessati sono invitati a partecipare. Per saperne di più sui prossimi seminari scrivete a babygeometri(a)cs.dm.unipi.it <https://student-web1.dm.unipi.it/squirrelmail/src/compose.php?send_to=babyg…> o consultate la nostra pagina web: http://people.dm.unipi.it/babygeometri/ Saluti, Giulio Belletti, Edoardo Fossati e Marco Moraschini

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Seminari oggi e domani
by Bruno Martelli 08 May '18

08 May '18

Buondì, Segnalo due seminari di geometria, oggi e domani (in due luoghi diversi). A presto, Bruno ----- 08-May-2018 - 15:00 Sala Conferenze (Puteano, Centro De Giorgi) <http://www.dm.unipi.it/webnew/it/aula/sala-conferenze-puteano-centro-de-gio…> Non-tangential convergence (and applications to holomorphic dynamics) <http://www.dm.unipi.it/webnew/it/seminari/non-tangential-convergence-and-ap…> Filippo Bracci The notion of non-tangential convergence is one of the basic concept of complex geoemtry in one and several variables. It is known that univalent maps from the disc into the complex plane admit non-tangential limit almost everywhere on the boundary of the disc, and Carathéodory’s prime ends theory fully describe the boundary behavior. However, starting with a simply connected domain, it is not clear in general when a given sequence in that domain converges non-tangentially to the boundary of the disc after pulling back via a Riemann map of the domain. The aim of this talk is to give a complete answer to such a question in terms of hyperbolic geometry, using Gromov’s hyperbolicity theory. Since every holomorphic self-map of the unit disc has a (essentially unique) holomorphic linearizing model (where dynamical properties of the map can be read via the geometry of the model domain), the previous characterization allows to study the type of convergence to the Denjoy-Wolff point for maps without inner fixed points. In this talk we will restrict ourselves mainly to the case of semigroups of holomorphic self-maps of the unit disc and show how to construct “pathological” examples of semigroups whose orbits converge to the Denjoy-Wolff point oscillating but non-tangentially, or partially tangential and partially non-tangentially. 09-May-2018 - 15:30 Sala Seminari (Dip. Matematica) <http://www.dm.unipi.it/webnew/it/aula/sala-seminari-dip-matematica> Slice-torus link invariants and Whitehead doubles <http://www.dm.unipi.it/webnew/it/seminari/slice-torus-link-invariants-and-w…>

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Seminario dei Baby Geometri
by Marco Moraschini 03 May '18

03 May '18

Cari tutti, vi segnalo questa attività per il ciclo di seminari dei Baby Geometri: Lunedì 7 Maggio alle 16:30 presso l'Aula Seminari del Dipartimento di Matematica Gianluca Faraco (Università degli Studi di Parma) terrà un seminario dal titolo: Be hyperbolic! Be pure! di cui riporto l'abstract: In this talk we will talk about the relationship between hyperbolic cone-structures and their holonomy representations. Any hyperbolic structure on a given closed compact and orientable surface S induces in a very natural way a representation of the fundamental group in the Lie group PSL(2,R), which encodes geometric data about the structure. The reverse problem to recover a hyperbolic cone-structure from a given representation is more arduous and longer. Even worse it is not always possible. In the first part of this talk we will consider this problem from a general viewpoint giving examples of representations that not arise as the holonomy of hyperbolic cone-structure. In the second part we focus our attention to a very special class of representations, namely purely hyperbolic representations. Tutti gli interessati sono invitati a partecipare. Per saperne di più sui prossimi seminari scrivete a babygeometri(a)cs.dm.unipi.it <https://student-web1.dm.unipi.it/squirrelmail/src/compose.php?send_to=babyg…> o consultate la nostra pagina web: http://people.dm.unipi.it/babygeometri/ Saluti, Giulio Belletti, Edoardo Fossati e Marco Moraschini

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