Prossimi Seminari

11 Marzo 2026

Aula 2

ore 10:30

Hilal Hama Karim

(Budapest)

Extremal (Turán) problems in planar graphs

-------------------------------------------------------

ore 11:30

Nils Kowalzig

(Roma Tor Vergata)

Tetramodules and a Takeuchi-Schneider equivalence

for Hopf algebroids

Abstract: 

Karim: The Turán number of a graph F is the maximum possible number of edges in n-vertex simple graphs without containing F as a subgraph. Through restricting the determination of this maximum to particular classes of graphs, various versions of the Turán number have been studied. One of the widely studied variants is the planar version. In this talk I will try to give an overview of planar Turán numbers, and present some of our recent results which are joint works with Ervin Györi.

Kowalzig:  Generalising results for Hopf algebras, we not only define the four possible types of Hopf modules in the bialgebroid setting but also yield the notion of two-sided two-cosided Hopf modules, also known as Hopf bimodules or tetramodules, in this realm. We prove that the category of Hopf bimodules can be endowed with the structure of a (pre-)braided monoidal category in two different ways, which, in turn, are shown to be both braided monoidally equivalent to the category of Yetter-Drinfel’d modules. This is done with thehelp of a fundamental theorem for Hopf modules via the concept of Hopf-Galois comodules, which also allows to prove a Takeuchi-Schneider correspondence theorem in the context of Hopf algebroid principal (quantum) homogeneous spaces.

Calendario Generale:

In rosso i seminari futuri.

• 11 marzo 2026, H. H. Karim (Budapest), Extremal (Turán) problems in planar graphs.

• 11 marzo 2026, , N. Kowalzig (Roma Tor Vergata), Tetramodules and a Takeuchi-Schneider equivalence for Hopf algebroids.

• 19 febbraio 2026, S. Halbig (Marburg), Applications of category theory, representation theory, and geometry in (topological) quantum computing.

• 19 febbraio 2026, T. Zorman (Hamburg), The Reflection equation and braided module categories

• 5 febbraio 2026, T. Weber, Quantization of infinitesimal braidings

• 29 Gennaio 2026, H. Chen (Xi'an Jiatong-Liverpool Un.), The Iwasawa µ-invariant of fine Selmer groups associated to general Drinfeld modules.

• 16 Dicembre 2025, G. Rosso (Concordia Un.), A non-archimedean Ax–Lindemann theorem for Shimura varieties.

• 12 Dicembre 2025, M. Abreu (Un. Basilicata), Factors and Hamiltonicity in regular graphs

• 29 Ottobre 2025, M. Mula (Bundeswehr Un.), Modular polynomials for cryptography: zero-knowledge from genus-zero modular curves

• 19 Giugno 2025, C. Sava (Charles Un.),  ∞-Dold-Kan correspondence via representation theory

• 26 Maggio 2025, G. Rosso (Concordia Un.), Specialness for non-archimedean varieties

• 25 Marzo 2025, M. Rossi (Milano Bicocca), Some results on the geometry of arithmetic random waves

• 25 Marzo 2025, G. Cherubini (INdAM), Boyd’s probabilistic model for harmonic numbers divisible by p

• 13 Marzo 2025, G. Bogo (Bielefeld), Picard-Fuchs differential equations for families of abelian varieties with real multiplication 

• 28 Febbraio 2025, F.M. Saettone (Weizmann Inst. Sc.), Equidistribution of CM points via Drinfeld uniformization and automorphic forms

• 20 Febbraio 2025, M. Longo (Padova), On the Tamagawa number conjecture for motives of modular forms

• 29 Gennaio 2025, D. Spriano (Oxford), No finitely generated group is indigestible for the Loch-Ness monster.

• 16 Gennaio 2025, A. Conti (Heidelberg), Bogomolov property for Galois representations with big local image.

• 13 Novembre 2024; F. Cioffi (Napoli), Cohen-Macaulay, Gorenstein and complete intersection conditions by marked bases on Hilbert schemes.

• [Mathlab] 30 Ottobre 2024, Y. Bugeaud (Strasbourg), On the decimal expansion of e.

• 1 Ottobre 2024, L. De Feo (IBM Zürich), The isogeny toolbox

• 28 Maggio 2024, F. Pellarin (Roma I), Some remarks on the factorization of the sine function

• 15 Maggio 2024, A. Conti (Luxembourg), Prime power congruences between Galois representations

• 11 Aprile 2024, M. Gran (Louvain-la-neuve), On the naturalness of Mal'tsev categories

• 15 Marzo 2024, J. Jenvrin (Grenoble), On the height of some generators of Galois extensions with big Galois groups