English
Related papers

Related papers: Commuting Contractive Families

200 papers

We prove the index theorem for elliptic operators acting on sections of bundles where fiber is equal to a projective module over a C*-algebra, in the situation of action of a compact Lie group on this algebra as well as on the total space…

Operator Algebras · Mathematics 2007-05-23 Evgenij V. Troitsky

Smith theory says that the fixed point of a semi-free action of a group $G$ on a contractible space is ${\bb Z}_p$-acyclic for any prime factor $p$ of $G$. Jones proved the converse of Smith theory for the case $G$ is a cyclic group acting…

Algebraic Topology · Mathematics 2022-02-21 Sylvain Cappell , Shmuel Weinberger , Min Yan

Recently the behavior of operator monotone functions on unbounded intervals with respect to the relation of strictly positivity has been investigated. In this paper we deeply study such behavior not only for operator monotone functions but…

Functional Analysis · Mathematics 2017-09-26 M. Fujii , M. S. Moslehian , H. Najafi , R. Nakamoto

In this series of two articles, we prove that every action of a finite group $G$ on a finite and contractible $2$-complex has a fixed point. The proof goes by constructing a nontrivial representation of the fundamental group of each of the…

Algebraic Topology · Mathematics 2025-08-22 Iván Sadofschi Costa

A classical result by Solodov states that if a group acts on the line such that any non-trivial element has at most one fixed point, then the action is either abelian or semi-conjugate to an affine action. We show that the same holds if we…

Group Theory · Mathematics 2022-10-17 João Carnevale

We introduce two notions of a contractive orbit of a set-valued map defined in a first countable space. The first defines the contraction with respect to the topology of the underlying space while the second defines the contraction with…

Functional Analysis · Mathematics 2026-02-10 Detelina Kamburova

In this paper, influenced by the ideas from A. Mihail, The canonical projection between the shift space of an IIFS and its attractor as a fixed point, Fixed Point Theory Appl., 2015, Paper No. 75, 15 p., we associate to every generalized…

Classical Analysis and ODEs · Mathematics 2018-03-20 Radu Miculescu , Silviu Urziceanu

We demonstrate new abstract characterizations for unital and non-unital operator spaces. We characterize unital operator spaces in terms of the cone of accretive operators (operators whose real part is positive). Defining the gauge of an…

Operator Algebras · Mathematics 2020-05-04 Travis B. Russell

We investigate some bounded linear operators T on a Hilbert space which satisfy the condition |T | less or equal to |ReT |. We describe the maximum invariant subspace for a contraction T on which T is a partial isometry to obtain that, in…

Functional Analysis · Mathematics 2015-12-01 Mostafa Mbekhta , Laurian Suciu

There are three main results in this paper. First, we find an easily computable and simple condition which is necessary and sufficient for a commuting tuple of contractions to possess a non-zero Toeplitz operator. This condition is just…

Functional Analysis · Mathematics 2019-06-05 Tirthankar Bhattacharyya , B. Krishna Das , Haripada Sau

In this article, a new class of operators, termed Ad-contractions, is introduced to extend the framework of A-contractions to the setting of dislocated metric spaces. Fixed point results are established for single mappings, sequences of…

General Topology · Mathematics 2025-07-22 Prasun Panthi , Dinesh Panthi

This note concerns uniform equicontinuity of families of operators on a separable Hilbert space H, and of families of maps on B(H). It is shown that a one parameter group of automorphisms is uniformly equicontinuous if and only if the group…

Functional Analysis · Mathematics 2007-05-23 Orr Shalit

Lin's theorem states that for all $\epsilon > 0$, there is a $\delta > 0$ such that for all $n \geq 1$ if self-adjoint contractions $A,B \in M_n(\mathbb{C})$ satisfy $\|[A,B]\|< \delta$ then there are self-adjoint contractions $A',B' \in…

Functional Analysis · Mathematics 2022-12-13 David Herrera

Consider two agents, Alice and Bob, each of whom takes a quantum input, operates on a shared quantum system $K$, and produces a quantum output. Alice and Bob's operations may commute, in the sense that the joint input-output behaviour is…

Quantum Physics · Physics 2023-08-14 Renato Renner , Ramona Wolf

We give a new and very short proof of a theorem of Greiner asserting that a positive and contractive $C_0$-semigroup on an $L^p$-space is strongly convergent in case that it has a strictly positive fixed point and contains an integral…

Functional Analysis · Mathematics 2017-06-06 Moritz Gerlach , Jochen Glück

A new, simple and unified approach in the theory of contractive mappings was recently given by Samet \emph{et al.} (Nonlinear Anal. 75, 2012, 2154-2165) by using the concepts of $\alpha$-$\psi$-contractive type mappings and…

Functional Analysis · Mathematics 2013-06-18 Priya Shahi , Jatinderdeep Kaur , S. S. Bhatia

A family of sets is said to be symmetric if its automorphism group is transitive, and $3$-wise intersecting if any three sets in the family have nonempty intersection. Frankl conjectured in 1981 that if $\mathcal{A}$ is a symmetric $3$-wise…

Combinatorics · Mathematics 2017-02-06 David Ellis , Bhargav Narayanan

We extend the fixed point result for Path-Averaged Contractions (PA-contractions) from complete metric spaces to complete b-metric spaces. We prove that every PA-contraction on a complete b-metric space has a unique fixed point, provided…

Functional Analysis · Mathematics 2025-12-25 Nicola Fabiano

Let $f: \mathbb{R}^d \to\mathbb{R}$ be a Lipschitz function. If $B$ is a bounded self-adjoint operator and if $\{A_k\}_{k=1}^d$ are commuting bounded self-adjoint operators such that $[A_k,B]\in L_1(H),$ then…

Operator Algebras · Mathematics 2017-03-10 Martijn Caspers , Fedor Sukochev , Dmitriy Zanin

We introduce the notion of a random relaxed asymptotic contraction in the setting of random normed modules. The contraction condition employs two quasi-metrics that are built directly from the random operator: a lower quasi-metric which…

Functional Analysis · Mathematics 2026-05-07 Jie Shi