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We establish some upper and lower bounds of the rational topological complexity for certain classes of elliptic spaces. Our techniques permit us in particular to show that the rational topological complexity coincides with the dimension of…

Algebraic Topology · Mathematics 2022-07-05 Said Hamoun , Youssef Rami , Lucile Vandembroucq

In this paper we present results concerning orthogonality in Hilbert $C^*$-modules. Moreover, for a $C^*$-algebra $\mathscr{A}$, we prove theorems concerning the multi-$\mathscr{A}$-linearity and its preservation by $\mathscr{A}$-linear…

Operator Algebras · Mathematics 2021-12-01 Pawel Wojcik , Ali Zamani

We study IE-closed subcategories of a module category, subcategories which are closed under taking Images and Extensions. We investigate the relation between IE-closed subcategories and torsion pairs, and characterize $\tau$-tilting finite…

Representation Theory · Mathematics 2022-08-31 Haruhisa Enomoto , Arashi Sakai

In this paper we provide a unifying description of different types of semantics of modal logic found in the literature via the framework of topological categories. In the style of categorical logic, we establish an exact correspondence…

Category Theory · Mathematics 2023-08-01 Lingyuan Ye

We explore various limit constructions for C*-algebras, such as composition series and inverse limits, in relation to the notions of real rank, stable rank, and extremal richness. We also consider extensions and pullbacks. We identify some…

Operator Algebras · Mathematics 2017-06-09 Lawrence G. Brown , Gert K. Pedersen

We study locally finitary realizations of simple transitive module categories of infinite rank over the monoidal category $\mathscr{C}$ of finite dimensional modules for the complex Lie algebra $\mathfrak{sl}_2$. Combinatorics of such…

Representation Theory · Mathematics 2024-05-31 Volodymyr Mazorchuk , Xiaoyu Zhu

A notion of rigidity with respect to an arbitrary semidualizing complex C over a commutative noetherian ring R is introduced and studied. One of the main result characterizes C-rigid complexes. Specialized to the case when C is the relative…

Commutative Algebra · Mathematics 2009-09-15 Luchezar L. Avramov , Srikanth B. Iyengar , Joseph Lipman

In this paper we classify extensions between irreducible finite conformal modules over the Virasoro algebra, over the current algebras and over their semidirect sums.

q-alg · Mathematics 2008-02-03 Shun-Jen Cheng , Victor Kac , Minoru Wakimoto

We study the termination of rewriting modulo a set of equations in the Calculus of Algebraic Constructions, an extension of the Calculus of Constructions with functions and predicates defined by higher-order rewrite rules. In a previous…

Logic in Computer Science · Computer Science 2016-08-16 Frédéric Blanqui

A series of associative algebras $A_n(V)$ for a vertex operator algebra $V$ over an arbitrary algebraically closed field and nonnegative integers $n$ are constructed such that there is a one to one correspondence between irreducible…

Quantum Algebra · Mathematics 2016-11-22 Li Ren

We classify all essential extensions of the form $$0 \rightarrow \W \rightarrow \D \rightarrow A \rightarrow 0$$ where $\W$ is the unique separable simple C*-algebra with a unique tracial state, with finite nuclear dimension and with…

Operator Algebras · Mathematics 2020-06-02 Huaxin Lin , Ping Wong Ng

Support $\tau$-tilting modules correspond to some classes of categorical objects bijectively, such as two-term tilting complexes for any finite dimensional symmetric algebra. This fact motivates us to classify support $\tau$-tilting modules…

Representation Theory · Mathematics 2020-04-28 Ryotaro Koshio , Yuta Kozakai

We set up a formalism of Maurer-Cartan moduli sets for L-infinity algebras and associated twistings based on the closed model category structure on formal differential graded algebras (a.k.a. differential graded coalgebras). Among other…

Algebraic Topology · Mathematics 2012-12-11 Andrey Lazarev

Some basic features of the simultaneous inclusion of discrete fibrations and discrete opfibrations on a category A in the category of categories over A are studied; in particular, the reflections and the coreflections of the latter in the…

Category Theory · Mathematics 2007-05-23 Claudio Pisani

Let $R$ be a commutative Noetherian ring with non-zero identity, $\fa$ an ideal of $R$, $M$ a finite $R$--module and $X$ an arbitrary $R$--module. Here, we show that, in the Serre subcategories of the category of $R$--modules, how the…

Commutative Algebra · Mathematics 2013-09-12 Alireza Vahidi , Moharram Aghapournahr

We develop the theory of a category ${\mathscr C}_A$ which is a generalisation to non-restricted ${\mathfrak g}$-modules of a category famously studied by Andersen, Jantzen and Soergel for restricted ${\mathfrak g}$-modules, where…

Representation Theory · Mathematics 2021-12-20 Matthew Westaway

The converse of Schur's lemma (or CSL) condition on a module category has been the subject of considerable study in recent years. In this note we extend that work by developing basic properties of module categories in which the CSL…

Rings and Algebras · Mathematics 2019-06-27 Greg Marks , Markus Schmidmeier

We introduce and characterize a particularly tractable class of unital type 1 C*-algebras with bounded dimension of irreducible representations. Algebras in this class are called recursive subhomogeneous algebras, and they have an inductive…

Operator Algebras · Mathematics 2007-05-23 N. Christopher Phillips

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

We define closed model category structures on different categories connected to the world of operad algebras over the category C(k) of (unbounded) complexes of k-modules: on the category of operads, on the category of algebras over a fixed…

q-alg · Mathematics 2008-02-03 Vladimir Hinich