Investigating the Rhaly Operator in Functional Analysis
This article examines the properties of the Rhaly operator with weighted null sequences.
― 5 min read
Table of Contents
This article discusses a specific type of mathematical operator, known as the Rhaly operator, and how it works with certain sequences of numbers. The focus is on understanding how this operator behaves in terms of Continuity, Compactness, and spectrum when applied to weighted null sequences.
Background
In mathematics, particularly in the area of functional analysis, many operators work with infinite sequences and matrices. When we refer to "weight vectors," we're talking about sequences that influence how the operator behaves. The Rhaly operator acts on these sequences, and researchers have been investigating its properties for some time. By studying these properties, we can understand better how these operators can be used in various mathematical contexts.
The Rhaly Operator
The Rhaly operator operates on a special type of matrix called a lower triangular terraced matrix. This specific type of matrix has some unique properties that make it interesting for study. When we apply the Rhaly operator to weighted null sequence spaces, which are specific arrangements of sequences, we can uncover a lot about how these operators behave.
Continuity and Compactness
Continuity in this context refers to how small changes in the input sequence affect the output of the operator. If a small change in the input leads to a small change in the output, we say the operator is continuous. Compactness is another property we look at; it helps determine whether the operator can be approximated by simpler operators acting on finite-dimensional spaces. We want to establish conditions under which the Rhaly operator retains these properties.
Spectral Properties
One of the main focuses of studying the Rhaly operator is its spectrum. The spectrum involves understanding the values for which the operator behaves in certain ways. We can break down the spectrum into three parts: the point spectrum, the continuous spectrum, and the residual spectrum. Each of these parts tells us something different about the operator's behavior.
Weighted Null Sequence Spaces
Weighted null sequence spaces consist of sequences where the terms are adjusted by positive weights. The term "null" refers to sequences whose elements tend toward zero. This combination creates spaces that have unique characteristics, allowing us to study operators more effectively.
Operator Ideals
Operator ideals are families of operators that share common properties. They play a significant role in functional analysis, allowing us to group operators that behave similarly. We introduce a new class of operator ideals that stems from the Rhaly operator and its relation to weighted sequence spaces.
Mathematical Notations and Concepts
Throughout this article, we utilize various mathematical notations. To simplify the discussion, we denote sequences and operators in standard forms. While the specific symbols might not be essential for the general understanding, they provide a concise way to express complex ideas. As we explore different properties, these notations help clarify the relationships between different elements.
Results on the Rhaly Operator
Boundedness and Compactness Conditions
We find that the Rhaly operator is bounded if specific conditions on the weight sequences are satisfied. This means that there is an upper limit to how much the operator can “stretch” the sequences it operates on. If the operator meets the criteria for boundedness, it helps in understanding its continuity and compactness as well.
Continuity
For the operator to be continuous, we study how the outputs behave as we change the inputs slightly. We need to check if small changes will not lead to wild swings in results.
Compactness
To determine compactness, we investigate whether the operator can be represented as a limit of operators with finite dimensions. If we can show this limit exists under certain conditions, we conclude that the operator is compact.
Spectral Analysis
Point Spectrum
The point spectrum consists of values where the operator behaves like an eigenvalue. Here, we look for specific sequences that yield non-zero solutions. By analyzing these relationships, we can identify certain characteristics of the operator.
Continuous Spectrum
The continuous spectrum arises when values do not lead to eigenvalues but still provide important information about the operator. These values indicate conditions under which the operator may still be relevant in applications.
Residual Spectrum
Lastly, the residual spectrum represents values where the operator does not have a point or continuous spectrum. This part gives insight into the limitations of the operator and where it might not have meaningful results.
Operator Ideal Class
The new class of operator ideals defined in this article showcases a fresh perspective on how operators interact within sequences. We establish several key properties for these ideals, demonstrating how they are structured and their significance in functional analysis.
Properties of the Ideal
The properties of the ideal include how it relates to operations within weighted sequence spaces and how functions mapping operators to sequences can preserve certain characteristics.
Quasi-Norms
We also introduce the concept of quasi-norms within this context. A quasi-norm helps determine how operators behave in relation to one another. If the operators fit certain criteria, they can be classified under this ideal.
Conclusion
This article provides a thorough exploration of the Rhaly operator and its implications in functional analysis. By studying continuity, compactness, and the spectrum, we gain valuable insights into how this operator functions within weighted null sequence spaces. The introduction of a new operator ideal class contributes to the ongoing research in the field, laying the groundwork for future studies.
The discussion extends the understanding of the interactions between operators and sequences, leading to a deeper comprehension of mathematical structures and their applications. With continued research in this area, we can expect to uncover even more about the fascinating world of functional analysis and its numerous applications.
Title: Spectral properties of the Rhaly operator on weighted null sequence spaces and associated operator ideals
Abstract: In this article, a comprehensive study is made on the continuity, compactness, and spectrum of the lower triangular terraced matrix, introduced by H. C. Rhaly, Jr. [Houston J. Math. 15(1): 137-146, 1989], acting on the weighted null sequence spaces with bounded, strictly positive weights. Several spectral subdivisions such as point spectrum, residual spectrum, and continuous spectrum are also discussed. In addition, a new class of operator ideal $\chi_{c_0(r)}^{(s)}$ associated to the Rhaly operator on weighted $c_0$ space is defined using the concept of $s$-number and it is proved that under certain condition, $\chi_{c_0(r)}^{(s)}$ forms a quasi-Banach closed operator ideal.
Authors: Arnab Patra, Jyoti Rani, Sanjay Kumar Mahto
Last Update: 2023-05-08 00:00:00
Language: English
Source URL: https://arxiv.org/abs/2305.04624
Source PDF: https://arxiv.org/pdf/2305.04624
Licence: https://creativecommons.org/licenses/by/4.0/
Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.
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