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Related papers: K-theory and perfection

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We study semigroup C*-algebras of $ax+b$-semigroups over integral domains. The goal is to generalize several results about C*-algebras of $ax+b$-semigroups over rings of algebraic integers. We prove results concerning K-theory and…

Operator Algebras · Mathematics 2013-06-25 Xin Li

Given a nilpotent Lie group $N$, a compact subgroup $K$ of automorphisms of $N$ and an irreducible unitary representation $(\tau,W_\tau)$ of $K$, we study conditions on $\tau$ for the commutativity of the algebra of…

Representation Theory · Mathematics 2020-02-18 Rocío Díaz Martín , Linda Saal

We apply the degree formula for connective $K$-theory to study rational contractions of algebraic varieties. Examples include rationally connected varieties and complete intersections.

Algebraic Geometry · Mathematics 2012-05-28 K. Zainoulline

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

The main objective of this paper is to propose a definition of non-connective K-theory for a wide class of relative exact categories which, in general, do not satisfy the factorization axiom and confirm that it agrees with the…

Algebraic Geometry · Mathematics 2013-03-19 Satoshi Mochizuki

We survey recent results on the representation theory of symplectic reflection algebras, focusing particularly on connections with symplectic quotient singularities and their resolutions, spaces of representations of quivers, and on…

Representation Theory · Mathematics 2007-12-11 Iain Gordon

We study the relative Frobenius map associated with a map of derived commutative rings over a field of positive characteristic. As part of this, we examine a relative analog of perfectness and construct a relative inverse limit perfection…

Commutative Algebra · Mathematics 2025-06-13 Daniel Fink

We prove that the Cuntz-Pimsner algebra O(E) of a vector bundle E over a compact metrizable space X is determined up to an isomorphism of C(X)-algebras by the ideal (1-[E])K(X) of the K-theory ring K(X). Moreover, if E and F are vector…

Operator Algebras · Mathematics 2010-04-27 Marius Dadarlat

We present a systematic study of join-extensions and join-completions of ordered algebras, which naturally leads to a refined and simplified treatment of fundamental results and constructions in the theory of ordered structures ranging from…

Logic · Mathematics 2017-08-17 José Gil-Férez , Luca Spada , Constantine Tsinakis , Hongjun Zhou

We consider the space of $n$-tuples of pairwise commuting elements in the Lie algebra of $U(m)$. We relate its one-point compactification to the subquotients of certain rank filtrations of connective complex $K$-theory. We also describe the…

Algebraic Topology · Mathematics 2024-10-10 Simon Gritschacher

We define united KK-theory for real C*-algebras A and B such that A is separable and B is sigma-unital, extending united K-theory in the sense that KK\crt(\R, B) = K\crt(B). United KK-theory contains real, complex, and self-conjugate…

Operator Algebras · Mathematics 2007-05-23 Jeffrey L. Boersema

We show that separable continuous fields over the unit interval whose fibers are stable Kirchberg algebras that satisfy the universal coefficient theorem in KK-theory and have rational K-theory groups are classified up to isomorphism by…

Operator Algebras · Mathematics 2013-11-05 Rasmus Bentmann , Marius Dadarlat

We establish comparison maps between the classical algebraic $K$-theory of algebras over a field and its analogue $K^c$, an algebraic $K$-theory for coalgebras over a field. The comparison maps are compatible with the Hattori--Stallings…

K-Theory and Homology · Mathematics 2026-04-23 Teena Gerhardt , Maximilien Péroux , W. Hermann B. Soré

In this note, we aim to prove the finite semi-algebraic chamber decomposition theorem for K-semi(poly)stability under the assumption of the log boundedness of K-semistable degenerations. This boundedness assumption is naturally arising from…

Algebraic Geometry · Mathematics 2025-09-22 Chuyu Zhou

A comprehensive review on Cook's contribution in the theory of NP-Completeness with relations to modern mathematics.

Computers and Society · Computer Science 2011-04-01 Li Chen

Given a completely rational conformal net A on the circle, its fusion ring acts faithfully on the K_0-group of a certain universal C*-algebra associated to A, as shown in a previous paper. We prove here that this action can actually be…

Operator Algebras · Mathematics 2018-10-16 Sebastiano Carpi , Roberto Conti , Robin Hillier

We prove in an elementary fashion that the image of a commutative monotone $\sigma$-complete $C^*$-algebra under a $\sigma$-normal morphism is again monotone $\sigma$-complete and give an application of this result in spectral theory.

Operator Algebras · Mathematics 2007-10-15 Marcel de Jeu

Kn\"orr has constructed an ideal, in the center of the p-modular group algebra of a finite group G, whose dimension is the number of p-blocks of defect zero in G/Q; here p is a prime and Q is a normal p-subgroup of G. We generalize his…

Group Theory · Mathematics 2023-09-28 Burkhard Külshammer

Kitchloo and Morava give a strikingly simple picture of elliptic cohomology at the Tate curve by studying a completed version of $S^1$-equivariant $K$-theory for spaces. Several authors (cf [ABG],[KM],[L]) have suggested that an equivariant…

Algebraic Topology · Mathematics 2022-07-22 Kiran Luecke

It is determined exactly which classifiable C*-algebras have approximately inner flip. The answer includes a number of C*-algebras with torsion in their K-theory, and a number of C*-algebras that are self-absorbing but not strongly…

Operator Algebras · Mathematics 2016-01-11 Aaron Tikuisis
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