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Related papers: Quasi-Isomorphisms of Commutative DG Rings and Div…

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Let \G be a (weak) quasi-Hopf algebra. Using a two-sided \G-coaction on an algebra \M, we construct what we call the diagonal crossed product as a new associative algebra structure on \M\otimes \dG, where \dG is the dual of \G. This…

q-alg · Mathematics 2008-02-03 Frank Hausser , Florian Nill

Let $O$ be a differential graded (possibly colored) operad defined over rationals. Let us assume that there exists a zig-zag of quasi-isomorphisms connecting $O \otimes K$ to its cohomology, where $K$ is any field extension of rationals. We…

K-Theory and Homology · Mathematics 2017-07-17 V. A. Dolgushev , G. E. Schneider

Quasi-elliptic cohomology is a variant of Tate K-theory. It is the orbifold K-theory of a space of constant loops. For global quotient orbifolds, it can be expressed in terms of equivariant K-theories. In this paper we show how this theory…

Algebraic Topology · Mathematics 2018-05-16 Zhen Huan

We consider the abelian group $PT$ generated by quasi-equivalence classes of pretriangulated DG categories with relations coming from semi-orthogonal decompositions of corresponding triangulated categories. We introduce an operation of…

Algebraic Geometry · Mathematics 2007-05-23 A. I. Bondal , M. Larsen , V. A. Lunts

We compare several quasi-Frobenius-type properties for corings that appeared recently in literature and provide several new characterizations for each of these properties. By applying the theory of Galois comodules with a firm coinvariant…

Rings and Algebras · Mathematics 2008-06-10 Joost Vercruysse

In this article we prove various results about transferring or lifting $\mathrm{A}_\infty$-algebra structures along quasi-isomorphisms over a commutative ring.

K-Theory and Homology · Mathematics 2025-10-24 Janina C. Letz

We show that a derived bi-duality dg-module is quasi-isomorphic to the homotopy limit of a certain tautological functor. This is a simple observation, which seems to be true in wider context. From the view point of derived Gabriel topology,…

Rings and Algebras · Mathematics 2012-10-23 Hiroyuki Minamoto

For a map f: X -> Y of quasi-compact quasi-separated schemes, we discuss quasi-perfection, that is, the right adjoint f^\times of the derived functor Rf_* respects small direct sums. This is equivalent to the existence of a functorial…

Algebraic Geometry · Mathematics 2011-11-09 Joseph Lipman , Amnon Neeman

Let k be a commutative ring with unit. We endow the categories of filtered complexes and of bicomplexes of k-modules, with cofibrantly generated model structures, where the class of weak equivalences is given by those morphisms inducing a…

Algebraic Topology · Mathematics 2020-12-09 Joana Cirici , Daniela Egas Santander , Muriel Livernet , Sarah Whitehouse

We prove a tamely ramified version of the Kazhdan-Lusztig equivalence using factorization algebras. More precisely, we establish an equivalence between the DG category of Iwahori-integrable affine Lie algebra representations and the DG…

Representation Theory · Mathematics 2021-11-30 Lin Chen , Yuchen Fu

We introduce the notion of a quasi DG category, generalizing that of a DG category. To a quasi DG category satisfying certain additional conditions, we associate another quasi DG category, the quasi DG category of $C$-diagrams. We then show…

Algebraic Geometry · Mathematics 2014-01-03 Masaki Hanamura

Recently, the rings whose injective right modules are R-projective (respectively, max-projective) were investigated and studied in [2]. Such ring are called right almost-QF (respectively, max-QF). In this paper, our aim is to give some…

Rings and Algebras · Mathematics 2024-04-03 Yusuf Alagöz , Engin Büyükaşık , Baran Yurtsever

Model sets play a fundamental role in structure analysis of quasicrystals. The diffraction diagram of a quasicrystal admits as symmetry group a finite group G, and there is a G-cluster C (union of orbits of G) such that the quasicrystal can…

Mathematical Physics · Physics 2007-05-23 Nicolae Cotfas

In this short paper we outline (mostly without proofs) our new approach to the derived category of sheaves of commutative DG rings. The proofs will appear in a subsequent paper. Among other things, we explain how to form the derived…

Algebraic Geometry · Mathematics 2016-08-16 Amnon Yekutieli

Let $D \subseteq A$ be a quasi-Cartan pair of algebras. Then there exists a unique discrete groupoid twist $\Sigma \to G$ whose twisted Steinberg algebra is isomorphic to $A$ in a way that preserves $D$. In this paper, we show there is a…

Rings and Algebras · Mathematics 2024-11-26 Jonathan H. Brown , Lisa Orloff Clark , Adam H. Fuller

We prove that homological filling functions over a ring $R$ equipped with the discrete norm are quasi-isometry invariants for all groups of type $\mathrm{FP}_n$. This confirms a conjecture of Bader-Kropholler-Vankov in the case of discrete…

Group Theory · Mathematics 2026-03-10 Jannis Weis

We define the notion of factorizable quasi-Hopf algebra by using a categorical point of view. We show that the Drinfeld double $D(H)$ of any finite dimensional quasi-Hopf algebra $H$ is factorizable, and we characterize $D(H)$ when $H$…

Quantum Algebra · Mathematics 2007-05-23 Daniel Bulacu , Blas Torrecillas

In this paper, we introduce the notion of Reidemeister torsion for quasi-isomorphisms of based chain complexes over a field. We call a chain map a quasi-isomorphism if its induced homomorphism between homology is an isomorphism. Our notion…

Algebraic Topology · Mathematics 2007-05-23 Jae-Wook Chung , Xiao-Song Lin

We introduce quasi-Gorenstein morphisms of commutative local dg-algebras and use a Gorenstein version of the virtually small property to characterize them, a result which is new even for homomorphisms of local rings. In a different…

Commutative Algebra · Mathematics 2026-05-05 Zachary Nason , Andrew J. Soto Levins , Ryan Watson

This paper is an MGM version of arXiv.org:1703.04266 and arXiv:1907.03364, and a follow-up to Section 5 of arXiv:1503.05523. In the setting of a commutative ring $S$ with a weakly proregular finitely generated ideal $J\subset S$, we…

Commutative Algebra · Mathematics 2025-12-08 Leonid Positselski