Multiplicity in root components via geometric Satake

نویسندگان

چکیده

In this note we explicitly construct top-dimensional components of certain cyclic convolution varieties. These correspond (via the geometric Satake equivalence) to irreducible summands V(λ+μ−Nβ)⊂V(λ)⊗V(μ) for SLn+1(C), where N≥1 and β is a positive root. Furthermore, deduce from these constructions nontrivial lower bound on multiplicity subrepresentations when not simple Finally, demonstrate that all such can be realized as closures orbits.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Twisted Geometric Satake Equivalence

Let k be an algebraically closed field and O = k[[t]] ⊂ F = k((t)). For an almost simple algebraic group G we classify central extensions 1 → Gm → E → G(F) → 1, any such extension splits canonically over G(O). Fix a positive integer N and a primitive character ζ : μN (k) → Q ∗ l (under some assumption on the characteristic of k). Consider the category of G(O)biinvariant perverse sheaves on E wi...

متن کامل

Geometric Satake, Springer Correspondence, and Small Representations

For a simply-connected simple algebraic group G over C, we exhibit a subvariety of its affine Grassmannian that is closely related to the nilpotent cone of G, generalizing a well-known fact about GLn. Using this variety, we construct a sheaf-theoretic functor that, when combined with the geometric Satake equivalence and the Springer correspondence, leads to a geometric explanation for a number ...

متن کامل

Affine Grassmannians and the Geometric Satake in Mixed Characteristic

We endow the set of lattices in Qp with a reasonable algebro-geometric structure. As a result, we prove the representability of affine Grassmannians and establish the geometric Satake correspondence in mixed characteristic. We also give an application of our theory to the study of Rapoport-Zink spaces.

متن کامل

Geršgorin Discs and Geometric Multiplicity

If A is an nxn complex matrix and λ is an eigenvalue of A with geometric multiplicity k, then λ is in at least k of the Geršgorin discs Di of A. Let k, r, t be positive integers with k ≤ r ≤ t . Then there is a t x t complex matrix A and an eigenvalue λ of A such that λ has geometric multiplicity k and algebraic multiplicity t, and λ is in precisely r Geršgorin Discs of A. Some examples and rel...

متن کامل

Geometric Satake, Springer Correspondence, and Small Representations Ii

Abstract. For a split reductive group scheme Ǧ over a commutative ring k with Weyl group W , there is an important functor Rep(Ǧ, k) → Rep(W, k) defined by taking the zero weight space. We prove that the restriction of this functor to the subcategory of small representations has an alternative geometric description, in terms of the affine Grassmannian and the nilpotent cone of the Langlands dua...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Communications in Algebra

سال: 2021

ISSN: ['1532-4125', '0092-7872']

DOI: https://doi.org/10.1080/00927872.2021.2015361