English
Related papers

Related papers: Shadows are Bicategorical Traces

200 papers

We study algebraic K-theory and topological Hochschild homology in the setting of bimodules over a stable category, a datum we refer to as a laced category. We show that in this setting both K-theory and THH carry universal properties, the…

Algebraic Topology · Mathematics 2026-03-03 Yonatan Harpaz , Thomas Nikolaus , Victor Saunier

We show that, if one allows for curved deformations, the canonical map introduced in [KL09] between Morita deformations and second Hochschild cohomology of a dg algebra becomes a bijection. We also show that a bimodule induces an…

K-Theory and Homology · Mathematics 2025-03-05 Alessandro Lehmann

We flesh out the theory of "trace theories" and "trace functors" sketched in arXiv:1308.3743, extend it to a homotopical setting, and prove a reconstruction theorem claiming that a trace theory is completely determined by the associated…

K-Theory and Homology · Mathematics 2021-07-06 D. Kaledin

The main purpose of this work is the study of the homotopy theory of dg-categories up to quasi-equivalences. Our main result provides a natural description of the mapping spaces between two dg-categories $C$ and $D$ in terms of the nerve of…

Algebraic Geometry · Mathematics 2007-05-23 B. Toen

Hochschild (co)homology and Pirashvili's higher order Hochschild (co)homology are useful tools for a variety of applications including deformations of algebras. When working with higher order Hochschild (co)homology, we can consider the…

Rings and Algebras · Mathematics 2017-12-04 Bruce R. Corrigan-Salter

We provide a direct proof that the Hochschild homology of a $\mathbb{Z}_2$-graded algebra is Morita invariant.

K-Theory and Homology · Mathematics 2009-05-28 Paul A. Blaga

A relative derived category for the category of modules over a presheaf of algebras is constructed to identify the relative Yoneda and Hochschild cohomologies with its homomorphism groups. The properties of a functor between this category…

Category Theory · Mathematics 2014-04-16 Alin Stancu

We point out a basic dichotomy between the shadowing and Lipschitz shadowing properties for one-sided shift spaces in two infinite-alphabet frameworks: the classical product-topology model $X\subseteq A^{\mathbb{N}}$ and the compact…

Dynamical Systems · Mathematics 2026-03-04 Daniel Gonçalves , Sofia Meneghel Silva

We use (non-)additive sheaves to introduce an (absolute) notion of Hochschild cohomology for exact categories as Ext's in a suitable bisheaf category. We compare our approach to various definitions present in the literature.

K-Theory and Homology · Mathematics 2011-04-19 Dmitry Kaledin , Wendy Lowen

One of the prime motivation for topology was Homotopy theory, which captures the general idea of a continuous transformation between two entities, which may be spaces or maps. In later decades, an algebraic formulation of topology was…

Category Theory · Mathematics 2025-11-24 Suddhasattwa Das

Let $G$ be a simple, simply-connected complex algebraic group with Lie algebra $\mathfrak{g}$, and $G/B$ the associated complete flag variety. The Hochschild cohomology $HH^\bullet(G/B)$ is a geometric invariant of the flag variety related…

Representation Theory · Mathematics 2025-01-17 Sam Jeralds

We prove an orbifold type decomposition theorem for the Hochschild homology of the symmetric powers of a small DG category $\mathcal{A}$. In noncommutative geometry, these can be viewed as the noncommutative symmetric quotient stacks of…

Algebraic Geometry · Mathematics 2026-01-01 Rina Anno , Vladimir Baranovsky , Timothy Logvinenko

Given a stable presentable infinity-category $\mathcal{E}$ equipped with a left complete t-structure, we prove that its Hochschild cohomology governs the deformation theory of $\mathcal{E}$ with respect to left complete t-structures.

Algebraic Geometry · Mathematics 2025-06-30 Isamu Iwanari

The classical HKR-theorem gives an isomorphism of the n-th Hochschild cohomology of a smooth algebra and the n-th exterior power of its module of K\"ahler differentials. Here we generalize it for simplicial, graded and anticommutative…

Algebraic Geometry · Mathematics 2007-05-23 Frank Schuhmacher

In this paper, we study the higher Hochschild functor and its relationship with factorization algebras and topological chiral homology. To this end, we emphasize that the higher Hochschild complex is a $(\infty,1)$-functor from the category…

Quantum Algebra · Mathematics 2012-06-01 Gregory Ginot , Thomas Tradler , Mahmoud Zeinalian

Reflexive homology is the homology theory associated to the reflexive crossed simplicial group; one of the fundamental crossed simplicial groups. It is the most general way to extend Hochschild homology to detect an order-reversing…

Algebraic Topology · Mathematics 2024-11-20 Daniel Graves

We show, up to h-cobordism, that the existence and uniqueness of connected sum decompositions of oriented 4-dimensional manifolds is an invariant of homotopy equivalence, assuming that the fundamental group of each summand is "good" in the…

Geometric Topology · Mathematics 2012-09-19 Qayum Khan

We discuss how the Hochschild cohomology of a dg category can be computed as the trace of its Serre functor. Applying this approach to the principal block of the Bernstein--Gelfand--Gelfand category $\mathcal{O}$, we obtain its Hochschild…

Representation Theory · Mathematics 2020-12-07 Clemens Koppensteiner

We write down a new "logarithmic" quasicoherent category $\operatorname{Qcoh}_{log}(U, X, D)$ attached to a smooth open algebraic variety $U$ with toroidal compactification $X$ and boundary divisor $D$. This is a (large) symmetric monoidal…

Algebraic Geometry · Mathematics 2017-12-04 Dmitry Vaintrob

We study the Hochschild homology of smooth spaces, emphasizing the importance of a pairing which generalizes Mukai's pairing on the cohomology of K3 surfaces. We show that integral transforms between derived categories of spaces induce,…

Algebraic Geometry · Mathematics 2010-05-25 Andrei Caldararu , Simon Willerton