Tikhonov regularization is a widely used technique in solving inverse problems that can enforce prior properties on the desired solution. In this talk, I will present a Krylov subspace based iterative method for solving linear inverse problems with general-form Tikhonov regularization term $x^top M x$ , where $M$ is a positive semidefinite matrix. An iterative […]
Title: Towards A-theory of orbifoldsAbstract: Waldhausen's A-theory of spaces — an extension of Quillen's higher algebraic K-theory of rings — is central to the study of moduli spaces of manifolds. In this talk, we will discuss a generalization of A-theory that takes as input an orbifold and which we expect to have rich geometric applications in analogy with the manifold setting. An orbifold is […]
Title: An Euler system of Heegner type Abstract: In this talk, I will present the result of Cornut in his paper "An Euler system of Heegner type" where he constructed the Kolyvagin Euler system associated with the spherical pair (SO(2n+1),U(n)) by reducing the local Horizontal norm relation to a divisibility result on integral Hecke module, […]
Topic: Formalizing ∞-Category Theory in Lean
Title: The Lawson-Osserman conjecture for the minimal surface systemAbstract: In their seminal work on the minimal surface system, Lawson and Osserman conjectured that Lipschitz graphs that are critical points of the area functional with respect to outer variations are also critical with respect to domain variations. We will discuss the proof of this conjecture for […]
Title: Relative Satake isomorphism and Euler systems Abstract: Starting from the inversion formula for the relative Satake isomorphism due to Sakellaridis, we observe a simple additional divisibility property. We will then explain how this gives a computation-free construction of Euler systems in some settings. This is joint work with Li Cai and Yangyu Fan.
Title: Towards the quantum exceptional series Abstract: Many Lie algebras fit into discrete families like GL(n), On, Spn. By work of Brauer, Deligne and others, the corresponding tensor categories fit into continuous familes GL(t) and OSp(t). A similar story holds for quantum groups, so we can speak of two parameter families GL(t)_q and OSp(t)_q. Thesetensor categories […]
Title: Introduction to Springer theory
Title: The Nevo-Thangavelu spherical maximal function on two step nilpotent Lie groups.Consider R^d times R^m with the group structure of a 2-step Carnot Lie group and natural parabolic dilations. The maximal operator originally introduced by Nevo and Thangavelu in the setting of the Heisenberg groups is generated by (noncommutative) convolution associated with measures on […]
Title: Minimal Exponent of Local Complete Intersection Subvarieties.Abstract: Classification of singularities is an interesting problem in many areas of algebraic geometry, like the minimal model program. One classical approach is to assign to a singular subvariety a rational number, its log canonical threshold. For complex hypersurface singularities, this invariant has been refined by M. Saito to the […]
Topic: Formalizing ∞-Category Theory in Lean