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We analyse a class of quantum field theory models illustrating some of the possibilities that have emerged in the general study of the short distance properties of superselection sectors, performed in a previous paper (together with R.…

Mathematical Physics · Physics 2010-11-11 Claudio D'Antoni , Gerardo Morsella

Let $T$ be a right exact functor from an abelian category $\mathscr{B}$ into another abelian category $\mathscr{A}$. Then there exists a functor ${\bf p}$ from the product category $\mathscr{A}\times\mathscr{B}$ to the comma category…

Rings and Algebras · Mathematics 2020-09-30 Jiangsheng Hu , Haiyan Zhu

For an orthogonal modular variety, we construct a complex which is defined in terms of lattices and elliptic modular forms, which resembles the Gersten complex in Milnor K-theory, and which has a morphism to the Gersten complex of the…

Algebraic Geometry · Mathematics 2026-01-21 Shouhei Ma

In this paper, we plan to build upon significant results by Amnon Neeman regarding the homotopy category of flat modules to study ${\mathbb{K}}({S\rm{SF}}\mbox{-}R)$, the homotopy category of $S$-strongly flat modules, where $S$ is a…

Commutative Algebra · Mathematics 2025-04-04 Javad Asadollahi , Somayeh Sadeghi

Let $A$ be a coherent algebra and $B$ be a finite-dimensional Gorenstein algebra over a field $k$. We describe finitely presented Gorenstein projective $A\otimes_k B$-modules in terms of their underlying onesided modules. Moreover, if the…

Representation Theory · Mathematics 2016-02-02 Dawei Shen

Consider a finite-dimensional algebra $A$ and any of its moduli spaces $\mathcal{M}(A,\mathbf{d})^{ss}_{\theta}$ of representations. We prove a decomposition theorem which relates any irreducible component of…

Representation Theory · Mathematics 2018-09-25 Calin Chindris , Ryan Kinser

For a connected semisimple algebraic group $G$, we consider some special infinite series of tensor products of simple $G$-modules whose $G$-fixed point spaces are at most one-dimensional. We prove that their existence is closely related to…

Representation Theory · Mathematics 2007-06-13 Vladimir L. Popov

In this paper we consider a construction in an arbitrary triangulated category T which resembles the notion of a Moore spectrum in algebraic topology. Namely, given a compact object C of T satisfying some finite tilting assumptions, we…

Category Theory · Mathematics 2010-06-03 David Pauksztello

In this paper we study finite dimensional algebras, in particular finite semifields, through their correspondence with nonsingular threefold tensors. We introduce a alternative embedding of the tensor product space into a projective space.…

Combinatorics · Mathematics 2024-03-14 Stefano Lia , John Sheekey

Given a finite dimensional algebra $\Lambda$, we show that a frequently satisfied finiteness condition for the category ${\cal P}^{\infty}(\Lambda\rm{-mod})$ of all finitely generated (left) $\Lambda$-modules of finite projective dimension,…

Representation Theory · Mathematics 2014-07-10 B. Huisgen-Zimmermann , S. O. Smalø

We extend the Auslander-Buchweitz axioms and prove Cohen-Macaulay approximation results for fibred categories. Then we show that these axioms apply for the fibred category of pairs consisting of a finite type flat family of Cohen-Macaulay…

Commutative Algebra · Mathematics 2019-08-06 Runar Ile

We establish a bijection between torsion pairs in the category of finite-dimensional modules over a finite-dimensional algebra A and pairs (Z, I) formed by a closed rigid set Z in the Ziegler spectrum of A and a set I of indecomposable…

Representation Theory · Mathematics 2024-03-04 Lidia Angeleri Hügel , Rosanna Laking , Francesco Sentieri

We study elementary Tate objects in an exact category. We characterize the category of elementary Tate objects as the smallest sub-category of admissible Ind-Pro objects which contains the categories of admissible Ind-objects and admissible…

K-Theory and Homology · Mathematics 2017-03-31 Oliver Braunling , Michael Groechenig , Jesse Wolfson

One proves that each almost local-global semihereditary ring has the stacked basis property and is almost Bezout. If M is a finitely presented module, its torsion part tM is a direct sum of cyclic modules where the family of annhilators is…

Rings and Algebras · Mathematics 2007-10-03 Francois Couchot

We will prove that over commutative rings the silting property of $2$-term complexes induced by morphisms between projective modules is preserved and reflected by faithfully flat extensions.

Representation Theory · Mathematics 2019-05-09 Simion Breaz

The relationship between comodules of a coring and flat connections is reviewed. In particular we specialise to corings which are built on a tensor product of algebra and a coalgebra. Such corings are in one-to-one correspondence with…

Quantum Algebra · Mathematics 2007-05-23 Tomasz Brzezinski

In a previous article (J. Algebra 367 (2012), 142-165) we established axiomatic parametrised Cohen-Macaulay approximation which in particular was applied to pairs consisting of a finite type flat family of Cohen-Macaulay rings and modules.…

Representation Theory · Mathematics 2021-03-23 Runar Ile

Given a homomorphism of commutative noetherian rings R --> S and an S-module N, it is proved that the Gorenstein flat dimension of N over R, when finite, may be computed locally over S. When, in addition, the homomorphism is local and N is…

Commutative Algebra · Mathematics 2007-05-23 Lars Winther Christensen , Srikanth Iyengar

This paper builds on top of arXiv:2306.02734. We consider a complete, separated topological ring $\mathfrak R$ with a countable base of neighborhoods of zero consisting of open two-sided ideals. The main result is that the homotopy category…

Rings and Algebras · Mathematics 2025-11-12 Leonid Positselski

Given a bounded-above cochain complex of modules over a ring, it is standard to replace it by a projective resolution, and it is classical that doing so can be very useful. Recently, a modified version of this was introduced in triangulated…

Category Theory · Mathematics 2023-12-20 Jesse Burke , Amnon Neeman , Bregje Pauwels