English
Related papers

Related papers: On relative complete reducibility

200 papers

Let G be a linear algebraic group defined over a field k. We prove that, under mild assumptions on k and G, there exists a finite k-subgroup S of G such that the natural map H^1(K, S) -> H^1(K, G) is surjective for every field extension…

Algebraic Geometry · Mathematics 2007-05-23 V. Chernousov , Ph. Gille , Z. Reichstein

Let G be a connected real reductive group. Orbit integrals define traces on the group algebra of G. We introduce a construction of higher orbit integrals in the direction of higher cyclic cocycles on the Harish-Chandra Schwartz algebra of…

K-Theory and Homology · Mathematics 2019-11-11 Yanli Song , Xiang Tang

We classify the linearly reductive finite subgroup schemes $G$ of $SL_2=SL(V)$ over an algebraically closed field $k$ of positive characteristic, up to conjugation. As a corollary, we prove that such $G$ is in one-to-one correspondence with…

Commutative Algebra · Mathematics 2014-03-07 Mitsuyasu Hashimoto

In this paper, we introduce the concept of a relative Heffter space which simultaneously generalizes those of relative Heffter arrays and Heffter spaces. Given a subgroup $J$ of an abelian group $G$, a relative Heffter space is a resolvable…

Combinatorics · Mathematics 2025-03-11 Laura Johnson , Lorenzo Mella , Anita Pasotti

We survey some of the known results on the relation between the homology of the {\em full} Hecke algebra of a reductive $p$-adic group $G$, and the representation theory of $G$. Let us denote by $\CIc(G)$ the full Hecke algebra of $G$ and…

K-Theory and Homology · Mathematics 2007-05-23 Victor Nistor

In math.RT/0302174 we developed a framework to study representations of groups of the form $G((t))$, where $G$ is an algebraic group over a local field $K$. The main feature of this theory is that natural representations of groups of this…

Representation Theory · Mathematics 2007-05-23 Dennis Gaitsgory , David Kazhdan

Let $G$ be a compact connected Lie group acting on a stable complex manifold $M$ with equivariant vector bundle $E$. Besides, suppose $\phi$ is an equivariant map from $M$ to the Lie algebra $\mathfrak{g}$. We can define some equivalence…

Symplectic Geometry · Mathematics 2013-01-23 Yanli Song

We prove that if $G$ is a noncompact connected real reductive linear Lie group, then any discrete subgroup of $G$ acting properly discontinuously and cocompactly on some homogeneous space $G/H$ of $G$ is quasi-isometrically embedded and…

Group Theory · Mathematics 2024-10-11 Fanny Kassel , Nicolas Tholozan

A minimal representation of a simple non-compact Lie group is obtained by ``quantizing'' the minimal nilpotent coadjoint orbit of its Lie algebra. It provides context for Roger Howe's notion of a reductive dual pair encountered recently in…

Mathematical Physics · Physics 2014-11-21 Ivan Todorov

The Grothendieck-Serre conjecture predicts that every generically trivial torsor under a reductive group $G$ over a regular semilocal ring $R$ is trivial. We establish this for unramified $R$ granted that $G^{\mathrm{ad}}$ is totally…

Algebraic Geometry · Mathematics 2025-11-24 Kestutis Cesnavicius , Roman Fedorov

We investigate Levi subgroups of a connected reductive algebraic group G, over a ground field K. We parametrize their conjugacy classes in terms of sets of simple roots and we prove that two Levi K-subgroups of G are rationally conjugate if…

Algebraic Geometry · Mathematics 2020-05-19 Maarten Solleveld

The theory of minimal K-types for p-adic reductive groups was developed in part to classify irreducible admissible representations with wild ramification. An important observation was that minimal K-types associated to such representations…

Algebraic Geometry · Mathematics 2020-05-21 Christopher L. Bremer , Daniel S. Sage

Let G denote a connected, quasi-split reductive group over a field F that is complete with respect to a discrete valuation and that has a perfect residue field. Under mild hypotheses, we produce a subset of the Lie algebra g(F) that picks…

Representation Theory · Mathematics 2019-03-13 Jeffrey D. Adler , Jessica Fintzen , Sandeep Varma

A theorem of L\"utkebohmert states that a rigid group homomorphism from the formal multiplicative group to a smooth commutative rigid group $G$, with relatively compact image, can be extended to a homomorphism from the rigid multiplicative…

Algebraic Geometry · Mathematics 2024-10-03 Martin Orr

We prove a number of structural and representation-theoretic results on linearly reductive quantum groups, i.e. objects dual to that of cosemisimple Hopf algebras: (a) a closed normal quantum subgroup is automatically linearly reductive if…

Quantum Algebra · Mathematics 2021-10-19 Alexandru Chirvasitu

Let X = G/H be a reductive symmetric space and K a maximal compact subgroup of G. The image under the Fourier transform of the space of K-finite compactly supported smooth functions on X is characterized.

Representation Theory · Mathematics 2007-05-23 E. P. van den Ban , H. Schlichtkrull

Let $G$ be a connected reductive subgroup of a complex connected reductive group $\hat{G}$. Fix maximal tori and Borel subgroups of $G$ and $\hat{G}$. Consider the cone $LR^\circ(\hat{G},G)$ generated by the pairs $(\nu,\hat{\nu})$ of…

Algebraic Geometry · Mathematics 2015-05-13 Nicolas Ressayre

Let G be a Lie group, $g = Lie(G)$ - its Lie algebra, $g*$ - the dual vector space and $\widehat G$ - the set of equivalence classes of unitary irreducible representations of $G$. The orbit method [1] establishes a correspondence between…

Representation Theory · Mathematics 2025-07-08 Dmitry Fuchs , Alexandre Kirillov

For an isotropic reductive group G satisfying a suitable rank condition over an infinite field k, we show that the sections of the $\mathbb{A}^1$-fundamental group sheaf of G over an extension field L/k can be identified with the second…

K-Theory and Homology · Mathematics 2016-03-29 Konrad Voelkel , Matthias Wendt

We develop the foundations of the theory of relatively geometric actions of relatively hyperbolic groups on CAT(0) cube complexes, a notion introduced in our previous work [5]. In the relatively geometric setting we prove: full relatively…

Group Theory · Mathematics 2022-03-09 Eduard Einstein , Daniel Groves