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We define tensor categories ${\sf Ver}_{p^n}(G)$ in characteristic $p$ for connected reductive groups $G$ and positive integers $n$, generalising the semisimple Verlinde categories ${\sf Ver}_p(G)$ originating from Gelfand-Kazhdan and the…

Representation Theory · Mathematics 2026-02-03 Joseph Newton

We define two-parameter families of noncommutative symmetric functions and quasi-symmetric functions, which appear to be the proper analogues of the Macdonald symmetric functions in these settings.

Combinatorics · Mathematics 2007-05-23 F. Hivert , A. Lascoux , J. -Y. Thibon

We incorporate covers of quasisplit reductive groups into the Langlands program, defining an L-group associated to such a cover. We work with all covers that arise from extensions of quasisplit reductive groups by $\mathbf{K}_2$ -- the…

Number Theory · Mathematics 2016-01-08 Martin H. Weissman

We describe generators and defining relations for the commutator subgroup of topological full groups of minimal subshifts. We show that the word problem in a topological full group is solvable if and only if the language of the underlying…

Group Theory · Mathematics 2015-09-17 Rostislav Grigorchuk , Konstantin Medynets

In this article, we improve our main results from \emph{Chow groups and $L$-derivatives of automorphic motives for unitary groups} in two direction: First, we allow ramified places in the CM extension $E/F$ at which we consider…

Number Theory · Mathematics 2021-04-13 Chao Li , Yifeng Liu

Let $H$ and $B$ be subgroups of a finite group $G$ such that $G=N_{G}(H)B$. Then we say that $H$ is \emph{quasipermutable} (respectively \emph{$S$-quasipermutable}) in $G$ provided $H$ permutes with $B$ and with every subgroup (respectively…

Group Theory · Mathematics 2013-05-01 Xiaolan Yi , Alexander N. Skiba

In the strict semi stable reduction situation, we describe the various filtrations of the perverse sheaf of nearby cycles in terms of irreducible perverse sheaves together with the action of the monodromy operator. We then study the…

Algebraic Geometry · Mathematics 2026-01-06 Pascal Boyer

This paper consists of three interconnected parts. Parts I,III study the relationship between the cohomology of a reductive group and that of a Levi subgroup. For example, we provide a necessary condition, arising from Kazhdan-Lusztig…

Group Theory · Mathematics 2007-05-23 B. Parshall , L. Scott

We classify the automorphic representations (over number fields) and the irreducible admissible representations (over local fields) of unitary groups which are not quasi-split, under the assumption that the same is known for quasi-split…

Number Theory · Mathematics 2014-12-04 Tasho Kaletha , Alberto Minguez , Sug Woo Shin , Paul-James White

Let F be a non-archimedean local field and let G be a connected reductive group defined over F. We assume that G splits over a tame extension of F and that the residual characteristic p does not divide the order of the Weyl group. To each…

Representation Theory · Mathematics 2021-02-15 Tasho Kaletha

We show that countable increasing unions preserve a large family of well-studied covering properties, which are not necessarily sigma-additive. Using this, together with infinite-combinatorial methods and simple forcing theoretic methods,…

General Topology · Mathematics 2018-04-06 Tal Orenshtein , Boaz Tsaban

We study the structure of nilpotent subsemigroups in the semigroup $M(n,\mathbb{F})$ of all $n\times n$ matrices over a field, $\mathbb{F}$, with respect to the operation of the usual matrix multiplication. We describe the maximal…

Group Theory · Mathematics 2010-04-02 Ganna Kudryavtseva , Volodymyr Mazorchuk

We give several equivalent characterisations of the maximal pro-2 quotients of real projective groups. In particular, for pro-2 real projective groups we provide a presentation in terms of generators and relations, and a purely…

Group Theory · Mathematics 2025-10-17 Ambrus Pál , Gereon Quick

In this paper we give a bijection between the class of permutations that can be drawn on an X-shape and a certain set of permutations that appears in [Knuth] in connection to sorting algorithms. A natural generalization of this set leads us…

Combinatorics · Mathematics 2007-10-29 Sergi Elizalde

It is proved that the numerical semigroups associated to the combinatorial configurations satisfy a family of non-linear symmetric patterns. Also, these numerical semigroups are studied for two particular classes of combinatorial…

Group Theory · Mathematics 2012-12-18 Klara Stokes , Maria Bras-Amorós

In this paper we explicitly determine all indicators for groups isomorphic to the semidirect product of two cyclic groups by an automorphism of prime order, as well as the generalized quaternion groups. We then compute the indicators for…

Representation Theory · Mathematics 2010-04-13 Marc Keilberg

Given a real inner product space $V$ and a group $G$ of linear isometries, we construct a family of $G$-invariant real-valued functions on $V$ that we call max filters. In the case where $V=\mathbb{R}^d$ and $G$ is finite, a suitable max…

Information Theory · Computer Science 2022-05-30 Jameson Cahill , Joseph W. Iverson , Dustin G. Mixon , Daniel Packer

We develop the representation theory of a finite semigroup over an arbitrary commutative semiring with unit, in particular classifying the irreducible and minimal representations. The results for an arbitrary semiring are as good as the…

Rings and Algebras · Mathematics 2010-04-13 Zur Izhakian , John Rhodes , Benjamin Steinberg

In this article, we show that for a quasicompact scheme $X$ and $n>0,$ the $n$-th $K$-group $K_{n}(X)$ is a $\lambda$-module over a $\lambda$-ring $K_{0}(X)$ in the sense of Hesselholt.

K-Theory and Homology · Mathematics 2024-01-05 Sourayan Banerjee , Vivek Sadhu

We characterize Markov lattice semigroups induced by measurable semiflows on probability spaces by properties of their generators. In addition we construct topological models on compact spaces for such semigroups.

Dynamical Systems · Mathematics 2020-10-15 Nikolai Edeko , Moritz Gerlach , Viktoria Kühner