20/03, 10:00h
Around non-commutative analogs of the Painlevé monodromy manifolds
Abstract: The famous differential Painlevé equations define the most general non-linear special functions. They are connected to various branches of mathematics as well as mathematical physics. In recent years, there has been growing interest in generalizing these equations to the non-commutative case, motivated by problematics and needs of modern physics. Furthermore, it is natural to study the properties of these non-commutative analogs, which extend those in the commutative setting. In particular, one may inquire about the non-commutative analogs of the so-called monodromy manifolds associated with the isomonodromic problems of the Painlevé equations.
In this talk, we will discuss a method for deriving these analogs and defining the associated Poisson structure. The talk is based on the paper arXiv:2302.10694 and an ongoing project in collaboration with S. Arthamonov.
19/03, 10:00h
On the interplay between ribbon graphs and CohFT
We will introduce the Cohomological Field Theories formalism and extend an axiomatic formulation of a 2D Topological Quantum Field Theory whose formalism is based on the edge-contraction operations on graphs drawn on a Riemann surface, that we call cellular graphs. We will describe a new result, that ribbon graphs provide both cohomological field theory and a visual explanation of the Frobenius-Hopf algebras duality. We will approach a classification result of Teleman for semi-simple Frobenius algebras via the theory of cellular graphs.
18/03, 16:15h
An example of Fock--Goncharov theory and Stokes data
This talk will focus on the study of a specific example of a meromorphic connection on the projective line. More precisely, it will be shown how the Stokes data arising from the higher order pole can be computed exploiting a triangulation of the decorated real oriented blowup of the surface involved. This way, Stokes data will arise as representations of specific automorphisms arising from Fock--Goncharov theory and the generalized monodromy matrices will be parametrized by Fock--Goncharov variables.
18/03, 12:30h
Resurgence of fermionic traces in toric Calabi-Yau threefolds
Quantizing the mirror curve of a toric Calabi-Yau threefold gives rise to quantum operators whose fermionic spectral traces produce factorially divergent series. In this talk, I will discuss the resurgence of these asymptotic series and present an exact solution for the spectral trace of weighted projective planes. This is based on a joint project with C. Rella.
19/03, 20/03, 21/03/25, 12:30h
Painlevé I tau function from irregular CFT, topological recursion and holomorphic anomaly
I will start by introducing the first Painlevé equation and the associated space of monodromy data. I will explain how the Fourier transform structure of the Painlevé I tau function arises from an extension of the Jimbo-Miwa-Ueno differential. We will then explore the connections between the main building block of this representation - the Painlevé I partition function - and three different topics: topological recursion, holomorphic anomaly equation and irregular conformal blocks.
Part One: 18/03/25, 10:00h
Part of a minicourse entitled: From Classical to Quantum Vistas: The Art of Geometric Quantization
From Newton to Schrödinger: Through the Quantum Looking Glass
Is our reality classical or quantum? The wave-particle duality hints at a world where both coexist, challenging our fundamental understanding of nature. Geometric quantization offers a path to bridge these realms, but there’s no universal formula—quantization is an art, blending intuition, structure, and deep mathematics.
This talk takes a dynamic journey through geometric quantization, from Darboux’s theorem to the Heisenberg uncertainty principle, exploring how symplectic geometry, polarization, and Bohr-Sommerfeld conditions shape the way we transition from classical observables to quantum operators. Along the way, we uncover the beauty, the paradoxes, and the ongoing quest to make sense of the quantum world.
Part Two: 19/03/25, 15:00h
Part of a minicourse entitled: From Classical to Quantum Vistas: The Art of Geometric Quantization
When Symmetry Meets Polytopes – A Path to Quantization
Symmetry is not just a fundamental principle in physics—it is a powerful tool that shapes how we transition from classical to quantum mechanics. In the process of quantization, symmetry and reduction principles become deeply intertwined. A particularly elegant approach arises from polytopes, which serve as blueprints for quantization in toric manifolds. In this setting, Bohr–Sommerfeld leaves align with integer lattice points, unveiling a rich interplay between symplectic geometry, combinatorial structures, and formal geometric quantization. This perspective not only provides a framework for quantizing symplectic manifolds but also extends naturally to certain classes of Poisson manifolds which are not symplectic.
20/03/2025, 16:15h
An introduction to the Narasimhan-Seshadri theorem
Abstract: I will give a very basic introduction, intended for graduate students, to the Narasimhan-Seshadri theorem. I will explain the context, the statement, the history, and I will very briefly describe the main ideas in the original proof by Narasimhan-Seshadri and the gauge theoretical proof of Donaldson.
21/03/2025, 10:00h
The Hitchin-Kobayashi correspondence for G-Higgs bundles
The Hitchin-Kobayashi correspondence is a vast generalization of the Narasimhan-Seshadri theorem. It lies at the heart of nonabelian Hodge theory, which relates Higgs bundles to local systems. I will explain the statement of the correspondence, paying special attention to the case where the structure group G is disconnected. Time permitting, I will say a few words on the techniques involved in the proof.
18/03/2025, 15:00h
Resurgence of the Deformed Painlevé I Equation
ABSTRACT: The first Painlevé equation with a perturbation parameter ħ is easy to solve in formal ħ-power series, but this solution is necessarily divergent. We prove that this divergent series is resurgent, which means it is Borel summable in almost every direction and the associated Stokes phenomenon is describable in terms of the Borel resummation of singularities of the Borel transform. In particular, the Borel transform of this formal solution admits endless analytic continuation with the following remarkable geometric structure: it naturally defines a global multivalued singular function on an algebraic surface isomorphic to the Fermat quintic surface x^5 + y^5 + z^5 = 0 modulo an involution. This surface is an algebraic fibration over the complex plane of the differential equation with the generic fibre a smooth quintic curve. The locus of singularities of the Borel transform intersects each fibre in exactly five points. Each fibre has a fivefold branched covering map to a complex plane (the Borel plane) with five ramification points of order five which are precisely the five singular points of the Borel transform. Based on joint work in preparation with M. Alameddine, O. Marchal, and N. Orantin.
21/03/2025, 11:15h
Regular F-manifolds
After recalling the notion of an F-manifold, as a geometric object generalising Frobenius manifolds and other structures, and of regularity, as a condition loosening the requirement of semisimplicity, we explain how to extend a number of precious constructions to some of such broader settings.
20/03/2025, 15:00h
Deformations and quantizations of moduli spaces of meromorphic connections on curves
The de Rham/Betti spaces of wild nonabelian Hodge theory parameterize isomorphism classes of meromorphic connections on principal bundles (or their monodromy/Stokes data). When the base of the bundle is a Riemann surface, they assemble into local systems of (complex) Poisson/symplectic algebraic varieties over any `admissible' deformation of the base: this goes beyond the deformations of pointed Riemann surfaces, due to the additional local moduli of irregular-singular connections at each pole, which lead in particular to cabled braid groups. Moreover, it possible to quantize the moduli spaces of meromorphic connections to construct (projectively) flat vector bundles over the same base, which instead lead to conformal blocks in the WZW model.
In this talk we will aim at a review of (a small) part of this story, and then describe extensions in the direction of:
(i) deformation quantization (based on past work with D. Calaque, G. Felder, R. Wentworth);
and (ii) the twisted/ramified case (based on work in progress with J. Douçot and past work with P. Boalch, J. Douçot, M. Tamiozzo).
21/03/2025, 15:00h
Bessel and beyond
I shall propose some elementary, less elementary and non-elementary aspects of classical solutions to Bessel equations.
I shall try to illustrate Yurii Manin’s principle of «Unity of Mathematics» on beautiful examples related to the Bessel functions.
18/03, 19/03, 20/03/25, 11:15h
A Hitchin connection for generalized theta functions on moduli of parabolic bundles
One of the most interesting examples of geometric quantization is the case of the moduli space of G-bundles on a compact Riemann surface. By analogy with the U(1) case, sections of the prequantum line bundle are called "generalized theta functions." In 1990 Hitchin proved the existence of a flat projective connection on the bundle of generalized theta functions where the Rieman surface structure is deformed. Later, Laszlo proved that the natural isomorphism with conformal blocks for the WZW CFT is flat with respect to the Hitchin and TUY/KZ connections. In these talks, I will outline a construction of a Hitchin connection where the surfaces are allowed to have marked points decorated with certain highest weight modules of G. The corresponding isomorphism with the bundle of conformal blocks is again flat. This is joint work with Indranil Biswas and Swarnava Mukhopadhyay.