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Related papers: Excision in algebraic K-theory revisited

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We find the general solution to the twisting equation in the tensor bialgebra $T({\bf R})$ of an associative unital ring ${\bf R}$ viewed as that of fundamental representation for a universal enveloping Lie algebra and its quantum…

Quantum Algebra · Mathematics 2015-06-26 Andrei Mudrov

Let G be a locally compact group, let X be a universal proper G-space, and let Z be a G-equivariant compactification of X that is H-equivariantly contractible for each compact subgroup H of G. Let W be the resulting boundary. Assuming the…

K-Theory and Homology · Mathematics 2015-10-23 Heath Emerson , Ralf Meyer

Let $k$ be a division ring and let $G$ be either a torsion-free virtually compact special group or a finitely generated torsion-free $3$-manifold group. We embed the group algebra $kG$ in a division ring and prove that the embedding is…

Group Theory · Mathematics 2025-02-21 Sam P. Fisher , Pablo Sánchez-Peralta

Let $f \colon X \to B$ be a complex elliptic surface and let $\DD \subset X$ be an integral divisor dominating $B$. It is well-known that the Parshin-Arakelov theorem implies the Mordell conjecture over complex function fields by a…

Algebraic Geometry · Mathematics 2019-12-09 Xuan Kien Phung

Let T be a torus, X a smooth quasi-compact separated scheme equipped with a T-action, and [X/T] the associated quotient stack. Given any localizing A1-homotopy invariant of dg categories E, we prove that the derived completion of E([X/T])…

Algebraic Geometry · Mathematics 2022-10-13 Gonçalo Tabuada , Michel Van den Bergh

Let $k$ be a field of characteristic $0$ and let $K = k(B)$ be the function field of a geometrically irreducible projective curve $B$ over $k$. Let $A/K$ be a $g$-dimensional abelian variety with $\mathrm{Tr}_{K/k}(A) = 0$. We prove that…

Number Theory · Mathematics 2026-03-25 Nicole Looper , Jit Wu Yap

We show that the twisted K-theory of the classifying space of a p-local finite group is isomorphic to the completion of the Grothendieck group of twisted representations of the fusion system with respect to the augmentation ideal of the…

Algebraic Topology · Mathematics 2021-04-23 Noe Barcenas , Jose Cantarero

We extend the notion of regular coherence from rings to additive categories and show that well-known consequences of regular coherence for rings also apply to additive categories. For instance the negative K-groups and all twisted…

K-Theory and Homology · Mathematics 2025-04-02 Arthur Bartels , Wolfgang Lueck

The Milnor-Wood inequality states that if a (topological) oriented circle bundle over an orientable surface of genus $g$ has a smooth transverse foliation, then the Euler class of the bundle satisfies $$|\mathcal{E}|\leq 2g-2.$$ We give a…

Geometric Topology · Mathematics 2025-12-04 Gaiane Panina , Timur Shamazov , Maksim Turevskii

Let $Q$ be a finite acyclic quiver and $A_Q$ the cluster algebra of $Q$. It is well-known that for each field $k$, the additive equivalence classes of support tilting $kQ$-modules correspond bijectively with the clusters of $A_Q$. The aim…

Representation Theory · Mathematics 2025-04-04 Osamu Iyama , Yuta Kimura

Given a cycle module M with a ring structure we show that the cycle complex with coefficients in M of a smooth scheme of finite type over a field has a A-infinity algebra structure. In the case of Milnor K-theory this gives a homotopy model…

Algebraic Geometry · Mathematics 2009-06-30 Florian Ivorra

We prove the formulae conjectured by the first author for the index of K-theory classes over the moduli stack of algebraic G-bundles on a smooth projective curve. The formulae generalise Verlinde's for line bundles and have Witten's…

Algebraic Geometry · Mathematics 2007-09-05 Constantin Teleman , Christopher T. Woodward

The Index theorem for holomorphic line bundles on complex tori asserts that some cohomology groups of a line bundle vanish according to the signature of the associated hermitian form. In this article, this theorem is generalized to…

Algebraic Geometry · Mathematics 2013-03-05 Tsz On Mario Chan

We study absolutely Koszul algebras, Koszul algebras with the Backelin-Roos property and their behavior under standard algebraic operations. In particular, we identify some Veronese subrings of polynomial rings that have the Backelin-Roos…

Commutative Algebra · Mathematics 2014-12-01 Aldo Conca , Srikanth B. Iyengar , Hop D. Nguyen , Tim Römer

Under mild assumptions, we characterise modules with projective resolutions of length n in the target category of filtrated K-theory over a finite topological space in terms of two conditions involving certain Tor-groups. We show that the…

Operator Algebras · Mathematics 2014-02-11 Rasmus Bentmann

In this note, we prove that given a smooth proper family over a $p$-adic ring of integers, one gets a control of its crystalline torsion in terms of its \'{e}tale torsion, the cohomological degree, and the ramification. Our technical core…

Algebraic Geometry · Mathematics 2025-06-17 Ofer Gabber , Shizhang Li

By analogy with algebraic geometry, we define a category of non-linear sheaves (quasi-coherent homotopy-sheaves of topological spaces) on projective toric varieties and prove a splitting result for its algebraic K-theory, generalising…

K-Theory and Homology · Mathematics 2010-07-30 Thomas Huettemann

We prove that the perfect loop functor $LX$ of a quasi-projective scheme $X$ over a local non-archimedean field $k$ satisfies arc-descent, strengthening a result of Drinfeld. Then we prove that for an unramified reductive group $G$, the map…

Algebraic Geometry · Mathematics 2021-09-06 Alexander B. Ivanov

We show that equivariant K-theory satisfies descent with respect to the isovariant Nisnevich topology. The main step is to show that the isovariant Nisnevich topology is a regular, complete and bounded cd topology.

K-Theory and Homology · Mathematics 2010-02-15 Christian Serpe

One of the major open problems in noncommutative algebraic geometry is the classification of noncommutative surfaces, and this paper resolves a significant case of this problem. Specifically, let S denote the 3-dimensional Sklyanin algebra…

Rings and Algebras · Mathematics 2016-01-20 D. Rogalski , S. J. Sierra , J. T. Stafford