For a closed oriented 3-manifold $M$, a discrete group $G$, a 3-cocycle $\alpha$ of $G$, and a representation $\rho \colon \pi_1(M) \to G$, the Dijkgraaf–Witten invariant is defined to be $\rho^\ast \alpha [M]$, where $[M]$ is the fundamental class…
Categoria evento: Seminars
Decomposition along a non-linear flag – Gabriele Vezzosi (Università di Firenze)
We define a non-commutative version of the punctured formal neighborhood in algebraic geometry, and apply this construction to give decompositions of the (derived) stacks $\mathbf{Coh}^-(X)$, $\mathbf{Perf}(X)$, and $\mathbf{Bun}_G(X)$ along a…
Canonical liftings and log structures – Piotr Achinger (Instytut Matematyczny PAN)
In the context of mirror symmetry, the moduli space of complex Calabi-Yau varieties acquires canonical local coordinates near a “large complex structure limit point”. In characteristic p geometry, the formal deformation space of an ordinary…
An introduction to the volume conjecture – Hiroaki Karuo ( RIMS – Tokyo University)
Title: An introduction to the volume conjecture Abstract:The volume conjecture is a conjecture between quantum topology andhyperbolic geometry. That states a certain limit of the colored Jonespolynomial of a knot would give the hyperbolic volume of…
Geometric finiteness in Hadamard manifolds – Beibei Liu (MPIM Bonn)
In this talk, we will focus on negatively pinched Hadamard manifolds which are complete, simply connected Riemannian manifolds with sectional curvature ranging between two negative constants. We use the techniques in geometric group theory to…
A bio-inspired optimization tool, the Dynamic Monge-Kantorovich model. Numerical solutions and applications – Enrico Facca (Scuola Normale Superiore, Pisa)
In this talk I will present the DynamicalMonge-Kantorovich model, a PDE system coupling an ellipticequation with a diffusion coefficient that change in timeaccording to a non-linear dynamics. The steady state of this system has been related to…
Deligne-Mostow lattices and come metrics on the sphere – Irene Pasquinelli (Paris Jussieu)
Finding lattices in PU(n,1) has been one of the major challenges of the last decades. One way of constructing a lattice is to give a fundamental domain for its action on the complex hyperbolic space. One approach, successful for some lattices,…
Operad dei piccoli n-Cubi. – Domenico Marasco (Università di Pisa)
Titolo: Operad dei piccoli n-Cubi. Abstract: Gli operad, definiti nel 1968 da Boardman e Vogt, descrivono in maniera elegante diversi tipi di strutture algebriche. In questo seminario lavoreremo con l’operad dei piccoli n-cubi C_n che, formato da…
Moduli spaces of Riemann surfaces: Models, Homology Operations, and Computations – Carl-Friedrich Bödigheimer (University of Bonn)
Il seminario sarà diviso in due parti, di 45 minuti ciascuna. La prima parte, di carattere introduttivo, sarà adatto anche ad un pubblico di non esperti (studenti di magistrale e dottorandi). L’abstract è scaricabile a questo link.…
Handling the conditioning of extreme-scale matrices – Massimiliano Fasi (Department of Mathematics, The University of Manchester)
In order to assess experimentally the stability of algorithms for the solution of systems of linear equations, it is typically desirable to have a certain degree of control over the condition number of the test matrices being used. If the tests are…