scholarly journals Asymptotic behaviour of non-autonomous dissipative systems in Hilbert space

1997 ◽  
Vol 62 (1) ◽  
pp. 93-103
Author(s):  
Song Guozhu
Keyword(s):  
Hilbert Space ◽  
Asymptotic Behaviour ◽  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Integral Solution ◽  
Dissipative Systems ◽  
Dissipative Operators ◽  
Linear Evolution ◽  
Linear Evolution Equation ◽  
Sufficient And Necessary Conditions

AbstractIn this paper we discuss the asymptotic behaviour, as t → ∞, of the integral solution u(t) of the non-linear evolution equation where {A(t)}t≥0 is a family of m-dissipative operators in a Hilbert space H, and g ∈ Lloc (0, ∞ H).We give some sufficient conditions and some sufficient and necessary conditions to ensure that are weakly convergent.

Efficiency of the weak Rescaled Pure Greedy Algorithm

2021 ◽  
pp. 2150001
Author(s):  
Bing Jiang ◽  
Peixin Ye
Keyword(s):  
Banach Space ◽  
Hilbert Space ◽  
Error Estimate ◽  
Banach Spaces ◽  
Greedy Algorithm ◽  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Pure Greedy Algorithm ◽  
Sufficient Conditions For Convergence ◽  
Sufficient And Necessary Conditions

We study the efficiency of the Weak Rescaled Pure Greedy Algorithm (WRPGA) with respect to a dictionary in a Hilbert space or more generally a Banach space. We obtain the sufficient and necessary conditions for the convergence of WRPGA for any element and any dictionary. This condition is weaker than the sufficient conditions for convergence of the Weak Pure Greedy Algorithm (WPGA). In addition, we establish the noisy version of the error estimate for the WRPGA, which implies the results on sparse classes obtained in [G. Petrova, Rescaled pure greedy algorithm for Hlibert and Banach spaces, Appl. Comput. Harmon. Anal. 41(3) (2016) 852–866].

Dynamics of an autonomous Gilpin–Ayala competition model with random perturbation

2021 ◽  
pp. 2050043
Author(s):  
Jing Fu ◽  
Qixing Han ◽  
Daqing Jiang ◽  
Yanyan Yang
Keyword(s):  
White Noise ◽  
Numerical Simulations ◽  
Positive Solution ◽  
Necessary Conditions ◽  
Random Perturbation ◽  
Sufficient Conditions ◽  
Competition Model ◽  
Interacting Species ◽  
Sufficient And Necessary Conditions ◽  
Global Positive Solution

This paper discusses the dynamics of a Gilpin–Ayala competition model of two interacting species perturbed by white noise. We obtain the existence of a unique global positive solution of the system and the solution is bounded in [Formula: see text]th moment. Then, we establish sufficient and necessary conditions for persistence and the existence of an ergodic stationary distribution of the model. We also establish sufficient conditions for extinction of the model. Moreover, numerical simulations are carried out for further support of present research.

scholarly journals A Distributed Approach to the Evasion Problem

Algorithms ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 149
Author(s):  
Denis Khryashchev ◽  
Jie Chu ◽  
Mikael Vejdemo-Johansson ◽  
Ping Ji
Keyword(s):  
Distributed Algorithm ◽  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Movement Pattern ◽  
Sheaf Theory ◽  
Distributed Approach ◽  
Sufficient And Necessary Conditions ◽  
Evasion Problem ◽  
Over Time ◽  
Path Detection

The Evasion Problem is the question of whether—given a collection of sensors and a particular movement pattern over time—it is possible to stay undetected within the domain over the same stretch of time. It has been studied using topological techniques since 2006—with sufficient conditions for non-existence of an Evasion Path provided by de Silva and Ghrist; sufficient and necessary conditions with extended sensor capabilities provided by Adams and Carlsson; and sufficient and necessary conditions using sheaf theory by Krishnan and Ghrist. In this paper, we propose three algorithms for the Evasion Problem: one distributed algorithm extension of Adams’ approach for evasion path detection, and two different approaches to evasion path enumeration.

scholarly journals Injectivity of linear combinations in $\mathcal{B}(\mathcal{H})$

2021 ◽  
Vol 37 ◽  
pp. 359-369
Author(s):  
Marko Kostadinov
Keyword(s):  
Linear Combination ◽  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Linear Combinations ◽  
Special Cases ◽  
Sufficient And Necessary Conditions ◽  
Alpha Beta ◽  
Necessary And Sufficient

The aim of this paper is to provide sufficient and necessary conditions under which the linear combination $\alpha A + \beta B$, for given operators $A,B \in {\cal B}({\cal H})$ and $\alpha, \beta \in \mathbb{C}\setminus \lbrace 0 \rbrace$, is injective. Using these results, necessary and sufficient conditions for left (right) invertibility are given. Some special cases will be studied as well.

scholarly journals Bounded sets in the range of anX∗∗-valued measure with bounded variation

2000 ◽  
Vol 23 (1) ◽  
pp. 21-30 ◽  
Author(s):  
B. Marchena ◽  
C. Piñeiro
Keyword(s):  
Banach Space ◽  
Hilbert Space ◽  
Bounded Variation ◽  
Necessary Conditions ◽  
Bounded Set ◽  
Sufficient And Necessary Conditions ◽  
Bounded Sets

LetXbe a Banach space andA⊂Xan absolutely convex, closed, and bounded set. We give some sufficient and necessary conditions in order thatAlies in the range of a measure valued in the bidual spaceX∗∗and having bounded variation. Among other results, we prove thatX∗is a G. T.-space if and only ifAlies inside the range of someX∗∗-valued measure with bounded variation wheneverXAis isomorphic to a Hilbert space.

Sums and products of quasi-nilpotent operators

1984 ◽  
Vol 99 (1-2) ◽  
pp. 193-200 ◽  
Author(s):  
C. K. Fong ◽  
A. R. Sourour
Keyword(s):  
Hilbert Space ◽  
Compact Operator ◽  
Necessary Conditions ◽  
Bounded Operator ◽  
Sufficient Conditions ◽  
Nilpotent Operators

SynopsisIt is proved that a bounded operator on Hilbert space is the sum of two quasi-nilpotent operators if and only if it is not a non-zero scalar plus a compact operator. Necessary conditions and sufficient conditions for an operator to be the product of two quasi-nilpotent operators are given.

Compactness of embeddings of function spaces on quasi-bounded domains and the distribution of eigenvalues of related elliptic operators

2013 ◽  
Vol 56 (3) ◽  
pp. 829-851 ◽  
Author(s):  
Hans-Gerd Leopold ◽  
Leszek Skrzypczak
Keyword(s):  
Asymptotic Behaviour ◽  
Spectral Properties ◽  
Necessary Conditions ◽  
Function Spaces ◽  
Elliptic Operators ◽  
Bounded Domains ◽  
Entropy Numbers ◽  
Sobolev Embeddings ◽  
Distribution Of Eigenvalues ◽  
Sufficient And Necessary Conditions

AbstractWe prove sufficient and necessary conditions for compactness of the Sobolev embeddings of Besov and Triebel–Lizorkin spaces defined on bounded and unbounded uniformly E-porous domains. The asymptotic behaviour of the corresponding entropy numbers is calculated. Some applications to the spectral properties of elliptic operators are described.

scholarly journals Second-Order Impulsive Delay Differential Systems: Necessary and Sufficient Conditions for Oscillatory or Asymptotic Behavior

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 722
Author(s):  
Shyam Sundar Santra ◽  
Khaled Mohamed Khedher ◽  
Osama Moaaz ◽  
Ali Muhib ◽  
Shao-Wen Yao
Keyword(s):  
Asymptotic Behavior ◽  
Differential System ◽  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Differential Systems ◽  
Sufficient And Necessary Conditions ◽  
Impulsive Delay ◽  
Delay Differential Systems ◽  
Delay Differential ◽  
Necessary And Sufficient

In this work, we aimed to obtain sufficient and necessary conditions for the oscillatory or asymptotic behavior of an impulsive differential system. It is easy to notice that most works that study the oscillation are concerned only with sufficient conditions and without impulses, so our results extend and complement previous results in the literature. Further, we provide two examples to illustrate the main results.

scholarly journals Necessary and sufficient conditions on weighted multilinear fractional integral inequality

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Zhou Yongliang ◽  
Deng Yangkendi ◽  
Wu Di ◽  
Yan Dunyan
Keyword(s):  
Integral Inequality ◽  
Sobolev Inequality ◽  
Fractional Integral ◽  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Integral Inequalities ◽  
Multilinear Fractional Integral ◽  
Sufficient And Necessary Conditions ◽  
Necessary And Sufficient

<p style='text-indent:20px;'>We consider certain kinds of weighted multi-linear fractional integral inequalities which can be regarded as extensions of the Hardy-Littlewood-Sobolev inequality. For a particular case, we characterize the sufficient and necessary conditions which ensure that the corresponding inequality holds. For the general case, we give some sufficient conditions and necessary conditions, respectively.</p>

scholarly journals Economic Dynamics under Heterogeneous Adaptive Learning: General Criteria and Sufficient Conditions for Stability

2019 ◽  
Vol 19 (4) ◽  
pp. 87-103
Author(s):  
A. S. Bogomolova ◽  
D. V. Kolyuzhnov
Keyword(s):  
Adaptive Learning ◽  
Necessary Conditions ◽  
Learning Algorithm ◽  
Sufficient Conditions ◽  
Dsge Models ◽  
Shock Process ◽  
Sufficient And Necessary Conditions ◽  
Process Behavior ◽  
The Stability ◽  
Sign Conditions

The article extends the results of Honkapohja and Mitra (2006) and Kolyuzhnov (2011) and provides criteria and sufficient conditions for stability in a structurally heterogeneous economy under heterogeneous adaptive learning of agents. The criteria for stability under heterogeneous mixed RLS/SG learning for four classes of models – without lags and with lags of the endogenous variable and with t or t – 1 – dating of expectations – and sufficient conditions for stability for the cases of the diagonal structure of the shock process behavior or the heterogeneous RLS learning are presented in terms of the corresponding Jacobian matrices. In addition, the study presents a very useful criterion for the stability for all types of models under mixed RLS/SG learning with equal degrees of inertia for each type of learning algorithm in terms of stability of a suitably defined average economy with two agents. The derived criteria and sufficient conditions for stability are based on the results of the theory of stochastic approximation and are presented in terms of mixture of structural and learning heterogeneity, which are essential to get sufficient and necessary conditions for stability irrespective of heterogeneity in learning presented in terms of E-stability of suitably defined aggregate economies, the “same sign” conditions and the E-stability of a suitably defined average economy and its subeconomies. The fundamental nature of the approach adopted in the paper makes it possible to apply the results to a vast majority of the existing and prospective linear and linearized economic models (including estimated DSGE models) with adaptive learning of agents.

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