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We consider a class of extensions of associative algebras, which we refer to as ``strongly proj-bounded extensions''. We prove that the finiteness of the left global dimension and the support of the Hochschild homology is preserved by…

K-Theory and Homology · Mathematics 2025-01-07 Kostiantyn Iusenko , John W. MacQuarrie

We prove in this note a result on extension of meromorphic mappings, which can be considered as a direct generalisation of the Hartogs extension theorem for holomorphic functions. Namely: THEOREM. Every meromorphic mapping $f:H_n^q(r)\to…

Complex Variables · Mathematics 2016-09-07 Sergei Ivashkovich , Alessandro Silva

Given a countable group $G$ and two subshifts $X$ and $Y$ over $G$, a continuous, shift-commuting map $\phi : X \to Y$ is called a homomorphism. Our main result states that if every finitely generated subgroup of $G$ has polynomial growth,…

Dynamical Systems · Mathematics 2025-09-10 Robert Bland , Kevin McGoff

In this paper we showed that every connected extremal K\"ahler submanifold of a complex projetive space has a natural extension which is a complete K\"ahler manifold and admits a holomorphic isometric immersion into the same ambient space.…

Differential Geometry · Mathematics 2023-06-29 Chao Li

We generalize Rado's extension theorem to complex spaces.

Complex Variables · Mathematics 2021-01-12 V. Vijiitu

We introduce notions of {\it upper chernrank} and {\it even cup length} of a finite connected CW-complex and prove that {\it upper chernrank} is a homotopy invariant. It turns out that determination of {\it upper chernrank} of a space $X$…

Algebraic Topology · Mathematics 2018-01-24 Bikram Banerjee

Let $A$ be a finite-dimensional algebra over a field $k$. We define $A$ to be $\mathbf{C}$-dichotomic if it has the dichotomy property of the representation type on complexes of projective $A$-modules. $\mathbf{C}$-dichotomy implies the…

Representation Theory · Mathematics 2025-12-09 Jie Li , Chao Zhang

Stasheff showed that if a map between H-spaces is an H-map, then the suspension of the map is extendable to a map between cprojective planes of the H-spaces. Stahseff also proved the converse under the assumption that the multiplication of…

Algebraic Topology · Mathematics 2007-05-23 Yutaka Hemmi

We first prove that for every metrizable space $X$, for every closed subset $F$ whose complement is zero-dimensional, the space $X$ can be embedded into a product space of the closed subset $F$ and a metrizable zero-dimensional space as a…

General Topology · Mathematics 2026-01-13 Yoshito Ishiki

The dimension algebra of graded groups is introduced. With the help of known geometric results of extension theory that algebra induces all known results of the cohomological dimension theory. Elements of the algebra are equivalence classes…

Algebraic Topology · Mathematics 2008-02-27 Jerzy Dydak

Recent research in coarse geometry revealed similarities between certain concepts of analysis, large scale geometry, and topology. Property A of G.Yu is the coarse analog of amenability for groups and its generalization (exact spaces) was…

Metric Geometry · Mathematics 2014-01-07 M. Cencelj , J. Dydak , A. Vavpetič

We first prove a version of Tietze-Urysohn's theorem for proper functions taking values in non-negative real numbers defined on $\sigma$-compact locally compact Hausdorff spaces. As its application, we prove an extension theorem of proper…

Metric Geometry · Mathematics 2022-12-27 Yoshito Ishiki

An extension of algebras is a homomorphism of algebras preserving identities. We use extensions of algebras to study the finitistic dimension conjecture over Artin algebras. Let $f: B \to A$ be an extension of Artin algebras. We denote by…

Rings and Algebras · Mathematics 2018-03-01 Shufeng Guo

Let $\Omega\subset\mathbb{C}^n$, $n\geq 2$, be a domain with smooth connected boundary. If $\Omega$ is relatively compact, the Hartogs-Bochner theorem ensures that every CR distribution on $\partial\Omega$ has a holomorphic extension to…

Complex Variables · Mathematics 2017-09-12 Al Boggess , Roman Dwilewicz , Egmont Porten

Our main result states that for each finite complex L the category ${\bf TOP}$ of topological spaces possesses a model category structure (in the sense of Quillen) whose weak equivalences are precisely maps which induce isomorphisms of all…

Algebraic Topology · Mathematics 2007-05-23 A. Chigogidze , A. Karasev

We recall the complex structure on the generalised loop spaces $W^{k,2}(S,X)$, where $S$ is a compact real manifold with boundary and $X$ is a complex manifold, and prove a Hartogs-type extension theorem for holomorphic maps from certain…

Complex Variables · Mathematics 2025-01-28 Mohammed Anakkar

We show that the difference of the extension dimensions of two derived equivalent algebras is bounded above by the minimal length of a tilting complex associated with a derived equivalence, and that the extension dimension is an invariant…

Representation Theory · Mathematics 2022-10-12 Jinbi Zhang , Junling Zheng

Let $A$ be any plane set. It is known that a holomorphic motion $h: A \times \mathbb{D} \to \mathbb{C}$ always extends to a holomorphic motion of the entire plane. It was recently shown that any isotopy $h: X \times [0,1] \to \mathbb{C}$,…

General Topology · Mathematics 2018-08-17 L. C. Hoehn , L. G. Oversteegen , E. D. Tymchatyn

We give a proof to the following theorem, which is well-known among experts: A connected subcomplex $W$ of a finite dimensional CAT(0) cubed complex $X$ is convex if and only if Lk$(v, W)$ is a full subcomplex of Lk$(v, X)$ for every vertex…

Geometric Topology · Mathematics 2023-03-21 Shunsuke Sakai , Makoto Sakuma

Suppose we are given complex manifolds $X$ and $Y$ together with substacks $\mathcal{S}$ and $\mathcal{S}'$ of modules over algebras of formal deformation $\mathcal{A}$ on $X$ and $\mathcal{A}'$ on $Y$, respectively. Suppose also we are…

Algebraic Geometry · Mathematics 2013-01-10 Ana Rita Martins , Teresa Monteiro Fernandes , David Raimundo