skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: A support theorem for\break the Hitchin fibration: The case of GL n and K C
Abstract We compute the supports of the perverse cohomology sheaves of the Hitchin fibration for GL n {\mathrm{GL}_{n}}over the locus of reduced spectral curves. In contrast to the case of meromorphic Higgs fields we find additional supports at the loci of reducible spectral curves. Their contribution to the global cohomology is governed by a finite twist of Hitchin fibrations for Levi subgroups. The corresponding summands give non-trivial contributions to the cohomology of the moduli spaces for every n 2 {n\geq{2}}. A key ingredient is a restriction result for intersection cohomology sheaves that allows us to compare the fibration to the one defined over versal deformations of spectral curves.  more » « less
Award ID(s):
1901975
PAR ID:
10468740
Author(s) / Creator(s):
; ;
Publisher / Repository:
De Gruyter
Date Published:
Journal Name:
Journal für die reine und angewandte Mathematik (Crelles Journal)
Volume:
2021
Issue:
780
ISSN:
0075-4102
Page Range / eLocation ID:
41 to 77
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract We study the family of irreducible modules for quantum affine 𝔰 𝔩 n + 1 {\mathfrak{sl}_{n+1}}whose Drinfeld polynomials are supported on just one node of the Dynkin diagram. We identify all the prime modules in this family and prove a unique factorization theorem. The Drinfeld polynomials of the prime modules encode information coming from the points of reducibility of tensor products of the fundamental modules associated to A m {A_{m}}with m n {m\leq n}. These prime modules are a special class of the snake modules studied by Mukhin and Young. We relate our modules to the work of Hernandez and Leclerc and define generalizations of the category 𝒞 - {\mathscr{C}^{-}}. This leads naturally to the notion of an inflation of the corresponding Grothendieck ring. In the last section we show that the tensor product of a (higher order) Kirillov–Reshetikhin module with its dual always contains an imaginary module in its Jordan–Hölder series and give an explicit formula for its Drinfeld polynomial. Together with the results of [D. Hernandez and B. Leclerc,A cluster algebra approach toq-characters of Kirillov–Reshetikhin modules,J. Eur. Math. Soc. (JEMS) 18 2016, 5, 1113–1159] this gives examples of a product of cluster variables which are not in the span of cluster monomials. We also discuss the connection of our work with the examples arising from the work of [E. Lapid and A. Mínguez,Geometric conditions for \square-irreducibility of certain representations of the general linear group over a non-archimedean local field,Adv. Math. 339 2018, 113–190]. Finally, we use our methods to give a family of imaginary modules in type D 4 {D_{4}}which do not arise from an embedding of A r {A_{r}}with r 3 {r\leq 3}in D 4 {D_{4}}. 
    more » « less
  2. Abstract A conjecture of Erdős states that, for any large primeq, every reduced residue class ( mod q ) {(\operatorname{mod}q)}can be represented as a product p 1 p 2 {p_{1}p_{2}}of two primes p 1 , p 2 q {p_{1},p_{2}\leq q}. We establish a ternary version of this conjecture, showing that, for any sufficiently large cube-free integerq, every reduced residue class ( mod q ) {(\operatorname{mod}q)}can be written as p 1 p 2 p 3 {p_{1}p_{2}p_{3}}with p 1 , p 2 , p 3 q {p_{1},p_{2},p_{3}\leq q}primes. We also show that, for any ε > 0 {\varepsilon>0}and any sufficiently large integerq, at least ( 2 3 - ε ) φ ( q ) {(\frac{2}{3}-\varepsilon)\varphi(q)}reduced residue classes ( mod q ) {(\operatorname{mod}q)}can be represented as a product p 1 p 2 {p_{1}p_{2}}of two primes p 1 , p 2 q {p_{1},p_{2}\leq q}.The problems naturally reduce to studying character sums. The main innovation in the paper is the establishment of a multiplicative dense model theorem for character sums over primes in the spirit of the transference principle. In order to deal with possible local obstructions we establish bounds for the logarithmic density of primes in certain unions of cosets of subgroups of q × {\mathbb{Z}_{q}^{\times}}of small index and study in detail the exceptional case that there exists a quadratic character ψ ( mod q ) {\psi~{}(\operatorname{mod}\,q)}such that ψ ( p ) = - 1 {\psi(p)=-1}for very many primes p q {p\leq q}. 
    more » « less
  3. Abstract Let 𝜋 and π \pi^{\prime}be cuspidal automorphic representations of GL ( n ) \mathrm{GL}(n)and GL ( n ) \mathrm{GL}(n^{\prime})with unitary central characters.We establish a new zero-free region for all GL ( 1 ) \mathrm{GL}(1)-twists of the Rankin–Selberg 𝐿-function L ( s , π × π ) L(s,\pi\times\pi^{\prime}), generalizing Siegel’s celebrated work on Dirichlet 𝐿-functions.As an application, we prove the first unconditional Siegel–Walfisz theorem for the Dirichlet coefficients of L ( s , π × π ) / L ( s , π × π ) -L^{\prime}(s,\pi\times\pi^{\prime})/L(s,\pi\times\pi^{\prime}).Also, for n 8 n\leq 8, we extend the region of holomorphy and nonvanishing for the twisted symmetric power 𝐿-functions L ( s , π , Sym n χ ) L(s,\pi,\mathrm{Sym}^{n}\otimes\chi)of any cuspidal automorphic representation of GL ( 2 ) \mathrm{GL}(2). 
    more » « less
  4. Abstract Let E / Q \mathrm{E}/\mathbb{Q}be an elliptic curve and 𝑝 a prime of supersingular reduction for E \mathrm{E}.Consider a quadratic extension L / Q p L/\mathbb{Q}_{p}and the corresponding anticyclotomic Z p \mathbb{Z}_{p}-extension L / L L_{\infty}/L.We analyze the structure of the points E ( L ) \mathrm{E}(L_{\infty})and describe two global implications of our results. 
    more » « less
  5. Abstract We show that the affine vertex superalgebra V k ( o s p 1 | 2 n ) V^{k}(\mathfrak{osp}_{1|2n})at generic level 𝑘 embeds in the equivariant 𝒲-algebra of s p 2 n \mathfrak{sp}_{2n}times 4 n 4nfree fermions.This has two corollaries:(1) it provides a new proof that, for generic 𝑘, the coset Com ( V k ( s p 2 n ) , V k ( o s p 1 | 2 n ) ) \operatorname{Com}(V^{k}(\mathfrak{sp}_{2n}),V^{k}(\mathfrak{osp}_{1|2n}))is isomorphic to W ( s p 2 n ) \mathcal{W}^{\ell}(\mathfrak{sp}_{2n})for = ( n + 1 ) + ( k + n + 1 ) / ( 2 k + 2 n + 1 ) \ell=-(n+1)+(k+n+1)/(2k+2n+1), and(2) we obtain the decomposition of ordinary V k ( o s p 1 | 2 n ) V^{k}(\mathfrak{osp}_{1|2n})-modules into V k ( s p 2 n ) W ( s p 2 n ) V^{k}(\mathfrak{sp}_{2n})\otimes\mathcal{W}^{\ell}(\mathfrak{sp}_{2n})-modules.Next, if 𝑘 is an admissible level and ℓ is a non-degenerate admissible level for s p 2 n \mathfrak{sp}_{2n}, we show that the simple algebra L k ( o s p 1 | 2 n ) L_{k}(\mathfrak{osp}_{1|2n})is an extension of the simple subalgebra L k ( s p 2 n ) W ( s p 2 n ) L_{k}(\mathfrak{sp}_{2n})\otimes{\mathcal{W}}_{\ell}(\mathfrak{sp}_{2n}).Using the theory of vertex superalgebra extensions, we prove that the category of ordinary L k ( o s p 1 | 2 n ) L_{k}(\mathfrak{osp}_{1|2n})-modules is a semisimple, rigid vertex tensor supercategory with only finitely many inequivalent simple objects.It is equivalent to a certain subcategory of W ( s p 2 n ) \mathcal{W}_{\ell}(\mathfrak{sp}_{2n})-modules.A similar result also holds for the category of Ramond twisted modules.Due to a recent theorem of Robert McRae, we get as a corollary that categories of ordinary L k ( s p 2 n ) L_{k}(\mathfrak{sp}_{2n})-modules are rigid. 
    more » « less