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Related papers: K-theoretic obstructions to bounded t-structures

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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

The main theorem in this paper is that the base change functor from an abelian category $\cA$ to its polynomial category in the sense of Schlichting $-\otimes_{\cA}\bbZ[t]:\cA \to \cA[t]$ induces an isomorphism on their $K$-theories if…

Commutative Algebra · Mathematics 2011-04-22 Satoshi Mochizuki , Akiyoshi Sannai

We define Grothendieck-Witt spectra in the setting of Poincar\'e $\infty$-categories and show that they fit into an extension with a K- and an L-theoretic part. As consequences we deduce localisation sequences for Verdier quotients, and…

We use controlled topology applied to the action of the infinite dihedral group on a partially compactified plane and deduce two consequences for algebraic K-theory. The first is that the family in the K-theoretic Farrell-Jones conjecture…

K-Theory and Homology · Mathematics 2015-11-30 James F. Davis , Frank Quinn , Holger Reich

Invoking the density argument of Dundas-Goodwillie-McCarthy, we extend the Fundamental Theorem of $K$-theory from the category of simplicial rings to the category of $\mathbb{S}$-algebras. As an intermediate step, we prove the Fundamental…

K-Theory and Homology · Mathematics 2020-04-21 Ernest E. Fontes , Crichton Ogle

A central question in equivariant algebraic K-theory asks whether there exists an equivariant K-theory machine from genuine symmetric monoidal G-categories to orthogonal G-spectra that preserves equivariant algebraic structures. We answer…

Algebraic Topology · Mathematics 2024-04-04 Donald Yau

Let $Q$ be an acyclic quiver and $w \geq 1$ be an integer. Let $\mathsf{C}_{-w} (\mathbf{k} Q)$ be the $(-w)$-cluster category of $\mathbf{k} Q$. We show that there is a bijection between simple-minded collections in $\mathsf{D}^b…

This article will explore the K- and L-theory of group rings and their applications to algebra, geometry and topology. The Farrell-Jones Conjecture characterizes K- and L-theory groups. It has many implications, including the Borel and…

Geometric Topology · Mathematics 2010-03-29 Wolfgang Lueck

We first prove that the K-theoretic Hall algebra of a preprojective algebra of affine type is isomorphic to the positive half of a quantum toroidal quantum group. An essential step consists to deform the K-theoretic Hall algebra so that the…

Representation Theory · Mathematics 2022-03-30 Michela Varagnolo , Eric Vasserot

We show that any bounded t-structure in the bounded derived category of a silting-discrete algebra is algebraic, i.e. has a length heart with finitely many simple objects. As a corollary, we obtain that the space of Bridgeland stability…

Representation Theory · Mathematics 2017-05-31 David Pauksztello , Manuel Saorín , Alexandra Zvonareva

In this paper we show that, for the Deligne exceptional series representations of negative integer level of affine Lie algebras, the quantum Hamiltonian reduction vanishes except for the cases where the nilpotent element is conjugate to…

Representation Theory · Mathematics 2024-09-02 Minoru Wakimoto

For ell a generic n-tuple of positive numbers, N(ell) denotes the space of isometry classes of oriented n-gons in R^3 with side lengths specified by ell. We determine the algebra K(N(ell)) and use this to obtain nonimmersions of the…

Algebraic Topology · Mathematics 2019-01-15 Donald M Davis

This paper is dedicated to the study of the kernel of the "compact motivization" functor $M_{k}^c:SH^c(k)\to DM^c(k)$ (i.e., we try to describe those compact objects of $SH(k)$ whose associated motives vanish. Moreover, we study the…

Algebraic Geometry · Mathematics 2019-12-17 Mikhail V. Bondarko

For a reductive group scheme $G$ over a semilocal Dedekind ring $R$ with total ring of fractions $K$, we prove that no nontrivial $G$-torsor trivializes over $K$. This generalizes a result of Nisnevich-Tits, who settled the case when $R$ is…

Algebraic Geometry · Mathematics 2020-07-23 Ning Guo

We prove a blow-up formula for cyclic homology which we use to show that infinitesimal $K$-theory satisfies $cdh$-descent. Combining that result with some computations of the $cdh$-cohomology of the sheaf of regular functions, we verify a…

K-Theory and Homology · Mathematics 2011-08-03 G. Cortiñas , C. Haesemeyer , M. Schlichting , C. A. Weibel

Let G be a smooth algebraic group acting on a variety X. Let F and E be coherent sheaves on X. We show that if all the higher Tor sheaves of F against G-orbits vanish, then for generic g in G, the sheaf Tor^X_j(gF, E) vanishes for all j >0.…

Algebraic Geometry · Mathematics 2009-08-21 Susan J. Sierra

In this paper, we study the quantum virtual Grothendieck ring, denoted by $\frakK_q(\g)$, which was introduced in [39], and further investigated in [26, 25]. Our approach involves examining this ring from two perspectives: first, by…

Quantum Algebra · Mathematics 2026-02-06 Kyu-Hwan Lee , Se-jin Oh

We define a genuine $\mathbb{Z}/2$-equivariant real algebraic $K$-theory spectrum $KR(A)$, for every genuine $\mathbb{Z}/2$-equivariant spectrum $A$ equipped with a compatible multiplicative structure. This construction extends the real…

Algebraic Topology · Mathematics 2019-08-14 Emanuele Dotto , Crichton Ogle

A discrete countable group G is matricially stable if the finite dimensional approximate unitary representations of G are perturbable to genuine representations in the point-norm topology. For large classes of groups G, we show that…

Operator Algebras · Mathematics 2021-03-19 Marius Dadarlat

We prove that negative K-groups of small abelian categories are trivial.

K-Theory and Homology · Mathematics 2013-06-04 Satoshi Mochizuki