Day 1

Francis Bischoff

Title: The derived moduli stack of logarithmic flat connections

Abstract: I will present an explicit finite-dimensional model for the derived moduli stack of flat connections on Ck with logarithmic singularities along a weighted homogeneous Saito free divisor. I will focus in particular on the example of plane curve singularities of the form xp = yq. These moduli spaces are conjectured to admit shifted Poisson structures. I will discuss this conjectural picture and present some partial results.

Song Gao

Title: Coisotropicity of Fixed points under torus action on the variety of Lagrangian subalgebras

Abstract: I will talk about my recent study of coisotropic subalgebras of Lie bialgebras. Given a complex semisim- ple Lie algebra g with adjoint group G, the set of coisotropic subalgebras of g form an algebraic variety, which is called the variety of coisotropic subalgebras. Let H be a fixed maximal torus of G. I will introduce my results on fixed points of H-action on the variety of coisotropic subalgebras. Approaches of toric varieties and algebraic groups will be used.

Yu Li

Title: Integrable systems on the dual of nilpotent Lie subalgebras and T -Poisson cluster structures

Abstract: Let g be a semisimple Lie algebra and g = n ⊕ h ⊕ n− a triangular decomposition. Motivated by a construction of Kostant-Lipsman-Wolf, we construct an integrable system on the dual space of n− equipped with the Kirillov-Kostant Poisson structure. The Bott-Samelson coordinates on the open Bruhat cell (equipped with the standard Poisson structure) makes it into a symmetric Poisson CGL extension, hence giving rise to a T-Poisson seed on it. We explain a relation between our integrable system and this T -Poisson seed. This is joint work in progress with Yanpeng Li and Jiang-Hua Lu.

Joshua Mundinger

Title: Quantization of restricted Lagrangian subvarieties in positive characteristic

Abstract: Bezrukavnikov and Kaledin introduced quantizations of symplectic varieties X in positive characteristic which endow the Poisson bracket on X with the structure of a restricted Lie algebra. We consider deformation quantization of line bundles on Lagrangian subvarieties Y of X to modules over such quantizations. If the ideal sheaf of Y is a restricted Lie subalgebra of the structure sheaf of X, we show that there is a certain cohomology class which vanishes if and only if a line bundle on Y admits a quantization.

Pavel Safronov

Title: Local structure of holomorphic Lagrangians and shifted Poisson geometry

Abstract: A Lagrangian submanifold of a real symplectic manifold has a neighborhood symplectomorphic to a neighborhood of the zero section of the cotangent bundle of the Lagrangian. Such a result is no longer true when working with complex manifolds. I will describe the obstruction in terms of a shifted Poisson structure. I will also present several related settings (Poisson-Lie groups, critical loci of Morse–Bott functions), where similar obstructions appear.

Theodore Voronov

Title: L-infinity comorphisms and duality for  L-infinity algebroids and P-infinity manifolds

Abstract: For Lie algebroids, there are two notions of a morphism:  "`morphisms" and "comorphisms" (due to Higgins--Mackenzie). Comorphisms  are dual to Poisson maps under   functorial constructions  E ↦ E*  and  M ↦ T*M. We introduce  a new notion  of   L-infinity comorphisms  of L-infinity algebroids (also its thick version)  and show how the functorial relations  between Lie algebroids and Poisson manifolds  extend    to the categories (P-infinity manifolds,   P-infinity morphisms) and (L-infinity algebroids, L-infinity comorphisms).
(Based on  joint  work  in progress with  Samuel  Brady.)


Day 2

Ana Balibanu

Title: Reduction of Dirac realizations

Abstract: We develop a general procedure for reduction along Dirac realizations, which are a broad generalization of Poisson momentum maps, and we recover a number of familiar constructions in Poisson and quasi-Poisson geometry. We use this approach to introduce new methods for reduction in the quasi-Poisson setting. As an appli- cation, we obtain quasi-Poisson structures on several classes of spaces that are studied in geometric representation theory.

Alberto Cattaneo

Title: Poisson structures from corners of field theories

Abstract: The BV formalism and its shifted versions in field theory have a nice compatibility with boundary structures. Namely, one such structure in the bulk induces a shifted (possibly degenerated) version on its boundary, which can be interpreted as a Poisson structure (up to homotopy). I will present the results for some field theories, in particular, 4D BF theory and 4D gravity.

Miguel Angel Evangelista-Alvarado

Title: Tutorial on Computational Poisson Geometry

Abstract: Poisson manifolds are generalizations of symplectic manifolds, informally as a space that is foliated by symplectic sheets. The Hamiltonian dynamics relative to the symplectic forms defined on each leaf are defined by the Poisson bracket.

Charlotte Kirchoff-Lukat

Title: The Fukaya category of the log symplectic sphere

Abstract: I will present my recent work on defining Floer cohomology and a Fukaya category for oriented log symplectic surfaces, with a focus on the higher A-infinity operations. This is a necessary first step to establishing mirror symmetry for log symplectic surfaces.

Praphulla Kumar Koushik Mudrakarta Chetlur Ramachandracharya

Title: On certain vector bundles over Dirac manifolds

Abstract: Motivated by the study of Poisson vector bundles over Poisson manifolds by Viktor Ginzburg in their work “Grothendieck Groups of Poisson Vector Bundles,” we introduce the notion of a certain vector bundle over Dirac manifolds and study certain properties. This will be based on our work in progress.

Aidan Lindberg

Title: Hodge theory of Poisson varieties and non-perturbative quantization

Abstract: Motivated by ideas of Kontsevich and deformation quantization, I will discuss a natural mixed Hodge structure on the topological K-theory of a smooth Poisson variety. In certain cases, we obtain Torelli-like parametrizations of the moduli space, which enable explicit, non-perturbative calculations of the associated deformation quantizations. The case of complex tori will be discussed in detail. This is based on joint work with B. Pym.

Joey Palmer

Title: Integrable systems and S1-actions: constructions and bifurcations

Abstract: Semitoric systems are a type of four-dimensional integrable system which admit a global S1-action; these systems were classified by Pelayo and Vu Ngoc in 2011, generalizing the classification of toric integrable systems. I will present some results about bifurcations of such systems, and show how this can be used to construct explicit examples of such systems with certain given invariants.

Tony Pantev

Title: Moduli of flat connections on smooth varieties

Abstract: I will discuss the derived geometry of the moduli of local systems and flat bundles on a smooth but not necessarily proper complex algebraic variety. In the Betti case I will show that these moduli carry natural Poisson structures, generalizing the well known case of curves.

Michael Shapiro

Title: Symplectic groupoid and Teichmueller space of closed genus two surfaces without boundary

Abstract: The symplectic groupoid of unipotent upper-triangular matrices is equipped with a natural Poisson bracket. We construct Darboux-type coordinates on symplectic groupoid. As a byproduct, we obtain coordinates on the Teichmueller space of genus two surfaces without boundary compatible with the Goldman Poisson bracket. To the best of our knowledge, this construction is new. It is a joint work with L. Chekhov.

Brian Williams

Title: The Poisson BV formalism and fivebranes

Abstract: The BV formalism is a mathematically effective way to formulate quantum field theory. We show how to encode the six-dimensional superconformal theory within a degenerate version of this formalism. An application to an enhancements of the AGT correspondence will also be given.

Shuyu Xiao

Title: Abelianization of Lie groupoids and Lie algebroids

Abstract: The abelianization of a Lie groupoid/algebroid is an abelian Lie groupoid/algebroid over the same base together with a projection map satisfying a certain universal property. The set-theoretical abelianization of the Weinstein groupoid, called the genus-integration can be thought of as a generalization of the Weinstein groupoid. The (smooth) abelianization does not always exist and might not ”commute” with the integration.


Day 3

Matias Luis del Hoyo

Title: Higher vector bundles

Abstract: In a joint work with G. Trentinaglia we develop a construction relating simplicial vector bundles and representations up to homotopy of Lie groupoids. I will briefly discuss the background, present our formulas, and mention some applications.

Ezra Getzler

Title: Homotopy moment maps for Chern-Simons theory

Daniel Hudson

Title: Weightings for Lie Groupoids and Lie Algebroids

Abstract: Weightings, or quasi-homogeneous structures, are a concept introduced by Melrose and later by Loizides and Meinrenken as a way to generalize the notion of order of vanishing. Loizides and Meinreken show that, given a weighting, one can define a ‘weighted normal bundle’ and a ‘weighted deformation space’ in a way that generalizes the standard normal bundle and standard deformation to the normal cone.

Lisa Jeffrey

Title: Poisson maps between character varieties

Abstract: We explore induced mappings between character varieties by mappings between surfaces. It is shown that these mappings are generally Poisson. We also discuss explicit mappings involving gluing together two surfaces with boundary, and capping boundaries with disks. Finally we show how this structure relates to the work of Alekseev, Malkin and Meinrenken on quasi-Hamiltonian manifolds. (Joint with Indranil Biswas, Jacques Hurtubise and Sean Lawton)

Ethan Ross

Title: An Introduction to Stratified Vector Bundles

Abstract: Stratified spaces are a kind of topological space together with a partition into smooth manifolds. These kinds of spaces naturally arise in the study of singular algebraic varieties, symplectic reduction, and differentiable stacks. In this talk, I will introduce a particular class of stratified space called stratified vector bundles. I will then provide large families of examples to try and justify why these are the reasonable notion of a vector bundle over a stratified space.

Ekaterina Shemyakova

Title: On super Plücker relations, super Ptolemy relations, and cluster algebras

Abstract: I will speak about super exterior powers and our results on super analogs of Plücker embedding for the Grassmann manifold. The problem was motivated by the search of the definition of super cluster algebras. Basing on the obtained super Plu ̈cker relations (which we have for the general case), we propose a super cluster structure for super Grassmannians Gr2|0(n|1).

Li-Sheng Tseng

Title: A Cone Story for Symplectic Manifolds

Abstract: I will motivate the use of pairs of differential forms with a map linking them to study manifolds. This leads to novel notions of flat connections and Morse theory for symplectic manifolds. Based on joint works with Jiawei Zhou, and David Clausen and Xiang Tang.

Luka Zwaan

Title: Duistermaat-Heckman results for Hamiltonian groupoid actions

Abstract: We attempt to generalise the classic Duistermaat-Heckman theorems to Hamiltonian actions of symplectic groupoids, using the theory of PMCTs.


Day 4

Yucong Jiang

Title: Symplectic double groupids in generalized Kahler geometry

Abstract: We will present a new way to view a GK metric in terms of Lagrangian branes in double symplectic Morita equivalences.

Caleb Jonker

Title: Generalized Curvature Operators and Deformations of Dirac Structures

Abstract: In this talk I will present results on the curvature operators associated to generalized connections. I will begin by reviewing the basic theory of generalized connections and their relationships to symmetries of the underlying Courant algebroid. Then I will explain an application of this theory to the generalized Chern connection that arises on the canonical bundle of a generalized Kähler manifold.

Kevin Morand

Title: Graph complexes and deformation quantization of Lie bialgebroids

Abstract: In the formulation of his celebrated Formality conjecture, M. Kontsevich introduced a graph version of the deformation theory for Poisson structures. In this talk, we will review Kontsevich’s graph construction and the rôle it plays in the quantization of Poisson manifolds before introducing a generalisation suitable to address the deformation quantization problem for Lie bialgebroids.

Kendric Schefers

Title: Microlocal homology and the shifted cotangent bundle

Abstract: Nadler’s microlocal homology is a family of invariants of a singular space that aims to capture the directions in which its singularities arise. Its definition a priori depends on the choice of presentation of the singular space as a special fiber of a map. In this talk, I outline recent work where I use the canonical sheaf of vanishing cycles on the shifted cotangent bundle of the derived special fiber to show the independence of the microlocal homology from our chosen presentation of the singular space.

Chenchang Zhu

Title: Higher differential geometry and symplectic structure

Abstract: In this talk, we will review the higher groupoid approach towards higher differentiable stacks and introduce shifted symplectic structures on them. We will give some interesting examples. Other topics, such as, possibility/path of quantisation, will be discussed if time permits. It is based on several joint works with Miquel Cueca Ten, Florian Dorsch, Leonid Ryvkin and Stefano Ronchi.