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Related papers: Excision in algebraic K-theory revisited

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In this work we introduce a new concept, namely, $\tau_{s}$-extending modules (rings) which is torsion-theoretic analogues of extending modules and then we extend many results from extending modules to this new concept. For instance we show…

Rings and Algebras · Mathematics 2022-01-03 Semra Dogruoz , Azime Tarhan

For a valuation ring $V$, a smooth $V$-algebra $A$, and a reductive $V$-group scheme $G$ satisfying a certain natural isotropicity condition, we prove that every Nisnevich $G$-torsor on $\mathbb{A}^N_A$ descends to a $G$-torsor on $A$. As a…

Algebraic Geometry · Mathematics 2025-05-09 Ning Guo , Fei Liu

In this paper we will prove a strong version of the celebrated purity of the ramification locus theorem in algebraic geometry. Our key input is a Tor-independence result for global sections of \'{e}tale schemes over excellent regular local…

Algebraic Geometry · Mathematics 2026-03-19 Ivan Zelich

We prove that algebraic K-theory, topological Hochschild homology and topological cyclic homology satisfy cubical and cosimplicial descent at connective structured ring spectra along 1-connected maps of such ring spectra.

Algebraic Topology · Mathematics 2022-06-22 Bjørn I. Dundas , John Rognes

The dimension of any module over an algebra of affiliated operators ${\mathcal U}$ of a finite von Neumann algebra ${\mathcal A}$ is defined using a trace on ${\mathcal A}.$ All zero-dimensional ${\mathcal U}$-modules constitute the torsion…

Rings and Algebras · Mathematics 2010-09-14 Lia Vas

The purpose of this work is to give a definition of a topological K-theory for dg-categories over C and to prove that the Chern character map from algebraic K-theory to periodic cyclic homology descends naturally to this new invariant. This…

K-Theory and Homology · Mathematics 2019-02-20 Anthony Blanc

We prove the Kirillov-Reshetikhin conjecture for all untwisted quantum affine algebras : we prove that the character of Kirillov-Reshetikhin modules solve the Q-system and we give an explicit formula for the character of their tensor…

Quantum Algebra · Mathematics 2007-05-23 David Hernandez

A universal coefficient theorem in the setting of Kirchberg's ideal-related KK-theory was obtained in the fundamental case of a C*-algebra with one specified ideal by Bonkat and proved there to split, unnaturally, under certain conditions.…

Operator Algebras · Mathematics 2013-09-05 Soren Eilers , Gunnar Restorff , Efren Ruiz

A new approach is established to computing the image of a rational map, whereby the use of approximation complexes is complemented with a detailed analysis of the torsion of the symmetric algebra in certain degrees. In the case the map is…

Commutative Algebra · Mathematics 2009-11-16 Laurent Busé , Marc Chardin , Aron Simis

Motivated by the splitting principle, we define certain simplicial complexes associated to an associative ring $A$, which have an action of the general linear group $GL(A)$. This leads to an exact sequence, involving Quillen's algebraic…

Algebraic Geometry · Mathematics 2015-03-17 M. V. Nori , V. Srinivas

We compare different algebraic structures in twisted equivariant K-Theory for proper actions of discrete groups. After the construction of a module structure over untwisted equivariant K-Theory, we prove a completion Theorem of Atiyah-Segal…

K-Theory and Homology · Mathematics 2019-01-15 Noe Barcenas , Mario Velasquez

We show that the convolution algebra of smooth, compactly-supported functions on a Lie groupoid is H-unital in the sense of Wodzicki. We also prove H-unitality of infinite order vanishing ideals associated to invariant, closed subsets of…

Operator Algebras · Mathematics 2023-10-06 Michael Francis

In this paper we continue the work of using the recent advances in algebraic $K$-theory to extend computations done in characteristic $p$ to the mixed characteristic setting using perfectoid rings. We extend the work of Hesselholt-Nikolaus…

K-Theory and Homology · Mathematics 2022-04-01 Noah Riggenbach

Let $f:A \to B$ be a ring homomorphism of not necessarily unital rings and $I\triangleleft A$ an ideal which is mapped by f isomorphically to an ideal of B. The obstruction to excision in K-theory is the failure of the map between relative…

K-Theory and Homology · Mathematics 2011-08-03 Guillermo Cortiñas

Let $\Phi$ be a family of functions analytic in some neighborhood of a complex domain $\Omega$, and let $T$ be a Hilbert space operator whose spectrum is contained in $\overline\Omega$. Our typical result shows that under some extra…

Functional Analysis · Mathematics 2017-03-28 Michael A. Dritschel , Daniel Estévez , Dmitry Yakubovich

We prove that the quantum moduli algebra associated to a possibly punctured compact oriented surface and a complex semisimple Lie algebra $\mathfrak{g}$ is a Noetherian and finitely generated ring. If the surface has punctures, we prove…

Quantum Algebra · Mathematics 2025-09-04 Stéphane Baseilhac , Matthieu Faitg , Philippe Roche

We show that the distributions occurring in the geometric and spectral side of the twisted Arthur-Selberg trace formula extend to non-compactly supported test functions. The geometric assertion is modulo a hypothesis on root systems proven…

Number Theory · Mathematics 2019-04-11 Abhishek Parab

We prove some fundamental results like localization, excision, Nisnevich descent and the Mayer-Vietoris property for equivariant regular blow-up for the equivariant K-theory of schemes with an affine group scheme action. We also show that…

Algebraic Geometry · Mathematics 2017-08-03 Amalendu Krishna , Charanya Ravi

Quillen introduced a new $K'_0$-theory of nonunital rings and showed that, under some assumptions (weaker than the existence of unity), this new theory agrees with the usual algebraic $K^{alg}_0$-theory. For a field $k$ of characteristic…

K-Theory and Homology · Mathematics 2015-03-29 Snigdhayan Mahanta

We construct a semi-orthogonal decomposition on the category of perfect complexes on the blow-up of a derived Artin stack in a quasi-smooth centre. This gives a generalization of Thomason's blow-up formula in algebraic K-theory to derived…

K-Theory and Homology · Mathematics 2020-09-15 Adeel A. Khan