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Related papers: On two group functors extending Schur multipliers

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In this article we describe extensions of some K-theory classes of Heisenberg modules over higher-dimensional noncommutative tori to projective modules over crossed products of noncommutative tori by finite cyclic groups, aka noncommutative…

Operator Algebras · Mathematics 2019-01-29 Sayan Chakraborty , Franz Luef

We apply down operators in the affine nilCoxeter algebra to yield explicit combinatorial expansions for certain families of non-commutative k-Schur functions. This yields a combinatorial interpretation for a new family of…

Combinatorics · Mathematics 2012-08-27 Chris Berg , Franco Saliola , Luis Serrano

We construct two-dimensional non-commutative topological quantum field theories (TQFTs), one for each Hecke algebra corresponding to a finite Coxeter system. These TQFTs associate an invariant to each ciliated surface, which is a Laurent…

Quantum Algebra · Mathematics 2021-12-20 Vladimir Fock , Valdo Tatitscheff , Alexander Thomas

For any imaginary quadratic field $K$, the Galois group $G_K$ of its maximal unramified pro-$3$-extension is a Schur $\sigma$-group. If this has Zassenhaus type $(3,3)$, there are 13 possibilities for the isomorphism class of the finite…

Number Theory · Mathematics 2026-02-11 Eric Ahlqvist , Richard Pink

We formulate a nonrecursive combinatorial rule for the expansion of the stable Grothendieck polynomials of [Fomin-Kirillov '94] in the basis of stable Grothendieck polynomials for partitions. This gives a common generalization, as well as…

Combinatorics · Mathematics 2010-02-17 Anders S. Buch , Andrew Kresch , Mark Shimozono , Harry Tamvakis , Alexander Yong

The problem of computing products of Schubert classes in the cohomology ring can be formulated as the problem of expanding skew Schur polynomials into the basis of ordinary Schur polynomials. In contrast, the problem of computing the…

Combinatorics · Mathematics 2016-06-30 Huilan Li , Jennifer Morse , Patrick Shields

For every profinite group $G$, we construct two covariant functors $\Delta_G$ and ${\bf {\mathcal {AP}}}_G$ from the category of commutative rings with identity to itself, and show that indeed they are equivalent to the functor $W_G$…

Rings and Algebras · Mathematics 2007-05-23 Young-Tak Oh

We study Translation functors and Wall-Crossing functors on infinite dimensional representations of a complex semisimple Lie algebra using D-modules. This functorial machinery is then used to prove the Endomorphism-theorem and the…

alg-geom · Mathematics 2008-02-03 Alexander Beilinson , Victor Ginzburg

Recently, the authors obtained the Schur multiplier, the non-abelian tensor square and the non-abelian exterior square of $d$-generator generalized Heisenberg Lie algebras of rank $ \frac{1}{2}d(d-1).$ Here, we intend to obtain the same…

Rings and Algebras · Mathematics 2021-10-12 Farangis Johari , Peyman Niroomand

Let ${\mathsf F}$ be the Schur functor from the category of finite dimensional ${\mathcal H}_{\vartriangle}(r)_\mathbb C$-modules to the category of finite dimensional ${\mathcal S}_{\vartriangle}(n,r)_{\mathbb{C}}$-modules, where…

Representation Theory · Mathematics 2016-01-20 Qiang Fu

In this paper we construct a GL-equivariant complex of Schur modules over a ring of positive characteristic that can be used to deduce classical alternating sum identities for Schur polynomials. This complex globalizes to a complex of…

Commutative Algebra · Mathematics 2022-03-25 Keller VandeBogert

We introduce a Milnor type $K$-group associated to commutative algebraic groups over a perfect field. It is an additive variant of Somekawa's $K$-group. We show that the $K$-group associated to the additive group and $q$ multiplicative…

K-Theory and Homology · Mathematics 2014-03-11 Toshiro Hiranouchi

Given a finite group $G$ and a subgroup $K$, we study the commutant of $\text{Ind}_K^G\theta$, where $\theta$ is an irreducible $K$-representation. After a careful analysis of Frobenius reciprocity, we are able to introduce an orthogonal…

Representation Theory · Mathematics 2024-06-25 Fabio Scarabotti , Filippo Tolli

We introduce two families of symmetric functions generalizing the factorial Schur $P$- and $Q$- functions due to Ivanov. We call them $K$-theoretic analogues of factorial Schur $P$- and $Q$- functions. We prove various combinatorial…

Combinatorics · Mathematics 2013-05-27 Takeshi Ikeda , Hiroshi Naruse

Consider a completely bounded Fourier multiplier phi of a locally compact group G, and take 1 <= p <= infinity. One can associate to phi a Schur multiplier on the Schatten classes S_p(L^2 G), as well as a Fourier multiplier on Lp(LG), the…

Functional Analysis · Mathematics 2017-10-05 Martijn Caspers , Mikael de la Salle

We define the Schur multipliers of a separable von Neumann algebra M with Cartan masa A, generalising the classical Schur multipliers of $B(\ell^2)$. We characterise these as the normal A-bimodule maps on M. If M contains a direct summand…

Operator Algebras · Mathematics 2018-08-22 Rupert H. Levene , Nico Spronk , Ivan G. Todorov , Lyudmila Turowska

The theory of noncommutative Schur functions can be used to obtain positive combinatorial formulae for the Schur expansion of various classes of symmetric functions, as shown by Fomin and Greene. We develop a theory of noncommutative super…

Combinatorics · Mathematics 2015-10-05 Jonah Blasiak , Ricky Ini Liu

There exists a covariant non-injective functor from the space of generic Riemann surfaces to the so-called toric AF-algebras; such a functor maps isomorphic Riemann surfaces to the stably isomorphic toric AF-algebras. We use the functor to…

Algebraic Geometry · Mathematics 2013-08-09 Igor Nikolaev

Many combinatorial generating functions can be expressed as combinations of symmetric functions, or extracted as sub-series and specializations from such combinations. Gessel has outlined a large class of symmetric functions for which the…

Combinatorics · Mathematics 2012-11-14 Frédéric Chyzak , Marni Mishna , Bruno Salvy

This paper develops two theories, the geometric theory of derived Grassmannians (and flag schemes) and the algebraic theory of derived Schur (and Weyl) functors, and establishes their connection, a derived generalization of the…

Algebraic Geometry · Mathematics 2023-07-10 Qingyuan Jiang