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Related papers: Some remarks on Nil groups in algebraic K-theory

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Let A be an arbitrary ring. We introduce a Dennis trace map mod n, from K_1(A;Z/n) to the Hochschild homology group with coefficients HH_1(A;Z/n). If A is the ring of integers in a number field, explicit elements of K_1(A,Z/n) are…

Number Theory · Mathematics 2009-10-31 Max Karoubi , Thierry Lambre

These lecture notes contain an exposition of basic ideas of K-theory and cyclic cohomology. I begin with a list of examples of various situations in which the K-functor of Grothendieck appears naturally, including the rudiments of the…

funct-an · Mathematics 2008-02-03 Jacek Brodzki

To any left system of diagram categories or to any left pointed derivateur (in the sense of Grothendieck) a K-theory space is associated. This K-theory space is shown to be canonically an infinite loop space and to have a lot of common…

K-Theory and Homology · Mathematics 2007-05-23 Grigory Garkusha

This paper investigates the Terwilliger algebra of some group association schemes related to codes. In addition, it also shows the generators of invariant rings appearing by E-polynomials.

Number Theory · Mathematics 2022-02-02 Nur Hamid

We develop the theory of ``branch algebras'', which are infinite-dimensional associative algebras that are isomorphic, up to taking subrings of finite codimension, to a matrix ring over themselves. The main examples come from groups acting…

Rings and Algebras · Mathematics 2009-11-27 Laurent Bartholdi

We establish vanishing results for the first cohomology group of nilpotent groups and Lie rings when the submodule of invariants is trivial. Our results are obtained within a model-theoretic setting, namely for structures that are definable…

Logic · Mathematics 2026-04-07 Samuel Zamour

Controlled topology is one of the main tools for proving the isomorphism conjecture concerning the algebraic $K$-theory of group rings. In this article we dive into this machinery in two examples: when the group is infinite cyclic and when…

K-Theory and Homology · Mathematics 2019-08-05 Eugenia Ellis , Emanuel Rodríguez Cirone , Gisela Tartaglia , Santiago Vega

We compute the groupoid homology for the ample groupoids associated with algebraic actions from rings of algebraic integers and integral dynamics. We derive results for the homology of the topological full groups associated with rings of…

Operator Algebras · Mathematics 2024-07-03 Chris Bruce , Yosuke Kubota , Takuya Takeishi

We show that Mandell's inverse $K$-theory functor is a categorically-enriched non-symmetric multifunctor. In particular, it preserves algebraic structures parametrized by non-symmetric operads. As applications, we describe how ring…

Algebraic Topology · Mathematics 2022-12-28 Niles Johnson , Donald Yau

The cyclotomic trace of B\"okstedt-Hsiang-Madsen, the subject of B\"okstedt's lecture at the congress in Kyoto, is a map of pro-abelian groups K_*(A) -> TR_*^.(A;p) from Quillen's algebraic K-theory to a topological refinement of Connes'…

Geometric Topology · Mathematics 2007-05-23 Lars Hesselholt

Coclass theory can be used to define infinite families of finite p-groups of a fixed coclass. It is conjectured that the groups in one of these infinite families all have isomorphic mod-p cohomology rings. Here we prove that almost all…

Group Theory · Mathematics 2015-03-31 Bettina Eick , David J. Green

It was shown by Rordam and the second named author that a countable group G admits an action on a compact space such that the crossed product is a Kirchberg algebra if, and only if, G is exact and non-amenable. This construction allows a…

Operator Algebras · Mathematics 2011-11-01 G. A. Elliott , A. Sierakowski

For $k, \ell \in \mathbb{N}$, we introduce the concepts of $k$-ultrahomogeneity and $\ell$-tuple regularity for finite groups. Inspired by analogous concepts in graph theory, these form a natural generalization of homogeneity, which was…

Group Theory · Mathematics 2024-04-09 Sofia Brenner

Algebraic cycles on complex projective space P(V) are known to have beautiful and surprising properties. Therefore, when V carries a real or quaternionic structure, it is natural to ask for the properties of the groups of real or…

Algebraic Topology · Mathematics 2012-08-27 H. Blaine Lawson, , Paulo Lima-Filho , Marie-Louise Michelsohn

We prove that the Farrell-Jones assembly map for connective algebraic K-theory is rationally injective, under mild homological finiteness conditions on the group and assuming that a weak version of the Leopoldt-Schneider conjecture holds…

K-Theory and Homology · Mathematics 2016-09-22 Wolfgang Lueck , Holger Reich , John Rognes , Marco Varisco

We prove in this paper that the periodic cyclic homology of the quantized algebras of functions on coadjoint orbits of connected and simply connected Lie group, are isomorphic to the periodic cyclic homology of the quantized algebras of…

Quantum Algebra · Mathematics 2007-05-23 Do Ngoc Diep , Aderemi O. Kuku

It is well known that to each infinite class of classical groups over a commutative ring $R$, we can associate an infinite loop space by Quillen's plus construction. In this paper we generalize this fact to the case of affine Kac-Moody…

Algebraic Topology · Mathematics 2011-04-14 Lin Xianzu

We compute explicitly the K-groups of some boundary groupoid C*-algebras with exponential isotropy subgroups. Then we derive index formulas that computes the K-theoretic and Fredholm indexes of elliptic (respectively totally elliptic)…

K-Theory and Homology · Mathematics 2018-04-30 Bing Kwan So

The K-theory of a functor may be viewed as a relative version of the K-theory of a ring. In the case of a Galois extension of a number field F/L with rings of integers A/B respectively, this K-theory of the "norm functor" is an extension of…

K-Theory and Homology · Mathematics 2009-09-29 Max Karoubi , Thierry Lambre

We compute the algebraic $K$-theory of some classes of surfaces defined over finite fields. We achieve this by first calculating the motivic cohomology groups and then studying the motivic Atiyah-Hirzebruch spectral sequence. In an…

Algebraic Geometry · Mathematics 2023-08-21 Oliver Gregory