scholarly journals On Functions Preserving Products of Certain Classes of Semimetric Spaces

2021 ◽  
Vol 78 (1) ◽  
pp. 175-198
Author(s):  
Mateusz Lichman ◽  
Piotr Nowakowski ◽  
Filip Tcroboś
Keyword(s):  
Triangle Inequality ◽  
Metric Spaces ◽  
Semimetric Spaces

Abstract In the paper, we continue the research of Borsík and Doboš on functions which allow us to introduce a metric to the product of metric spaces. We extend their scope to a broader class of spaces which usually fail to satisfy the triangle inequality, albeit they tend to satisfy some weaker form of this axiom. In particular, we examine the behavior of functions preserving b-metric inequality. We provide analogues of the results of Borsík and Doboš adjusted to the new broader setting. The results we obtained are illustrated with multitude of examples. Furthermore, the connections of newly introduced families of functions with the ones already known from the literature are investigated.

scholarly journals On statistical convergence in quasi-metric spaces

2019 ◽  
Vol 52 (1) ◽  
pp. 225-236 ◽  
Author(s):  
Merve İlkhan ◽  
Emrah Evren Kara
Keyword(s):  
Functional Analysis ◽  
Computer Science ◽  
Distance Function ◽  
Metric Space ◽  
Statistical Convergence ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Applied Mathematics ◽  
Comprehensive Investigation ◽  
Cauchy Sequences

AbstractA quasi-metric is a distance function which satisfies the triangle inequality but is not symmetric in general. Quasi-metrics are a subject of comprehensive investigation both in pure and applied mathematics in areas such as in functional analysis, topology and computer science. The main purpose of this paper is to extend the convergence and Cauchy conditions in a quasi-metric space by using the notion of asymptotic density. Furthermore, some results obtained are related to completeness, compactness and precompactness in this setting using statistically Cauchy sequences.

scholarly journals Extended Partial Sb-Metric Spaces

Axioms ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 87 ◽  
Author(s):  
Aiman Mukheimer
Keyword(s):  
Fixed Point ◽  
Fixed Point Theorems ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Control Function

In this paper, we introduce the concept of extended partial S b -metric spaces, which is a generalization of the extended S b -metric spaces. Basically, in the triangle inequality, we add a control function with some very interesting properties. These new metric spaces generalize many results in the literature. Moreover, we prove some fixed point theorems under some different contractions, and some examples are given to illustrate our results.

scholarly journals Double Controlled Metric Type Spaces and Some Fixed Point Results

Mathematics ◽  
2018 ◽  
Vol 6 (12) ◽  
pp. 320 ◽  
Author(s):  
Thabet Abdeljawad ◽  
Nabil Mlaiki ◽  
Hassen Aydi ◽  
Nizar Souayah
Keyword(s):  
Fixed Point ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Type Space ◽  
Control Functions ◽  
Right Hand ◽  
Type Spaces ◽  
The Right ◽  
The Given

In this article, in the sequel of extending b-metric spaces, we modify controlled metric type spaces via two control functions α ( x , y ) and μ ( x , y ) on the right-hand side of the b - triangle inequality, that is, d ( x , y ) ≤ α ( x , z ) d ( x , z ) + μ ( z , y ) d ( z , y ) , for all x , y , z ∈ X . Some examples of a double controlled metric type space by two incomparable functions, which is not a controlled metric type by one of the given functions, are presented. We also provide some fixed point results involving Banach type, Kannan type and ϕ -nonlinear type contractions in the setting of double controlled metric type spaces.

scholarly journals Properties of distance spaces with power triangle inequalities

2016 ◽  
Vol 8 (1) ◽  
pp. 51-82
Author(s):  
D. Greenhoe
Keyword(s):  
Triangle Inequality ◽  
Metric Spaces ◽  
Geometric Mean ◽  
Power Mean ◽  
Exponential Parameter ◽  
Triangle Function ◽  
Special Cases ◽  
Two Parameter ◽  
Parameter Relation ◽  
Maximum Minimum

Metric spaces provide a framework for analysis and have several very useful properties. Many of these properties follow in part from the  triangle inequality. However, there are several applications in which the triangle inequality does not hold but in which we may still like to perform analysis. This paper investigates what happens if the triangle inequality is removed all together, leaving what is called a distance space, and also what happens if the triangle inequality is replaced with a much more general two parameter relation, which is herein called the "power triangle inequality". The power triangle inequality represents an uncountably large class of inequalities, and includes the  triangle inequality,  relaxed triangle inequality, and   inframetric inequality as special cases. The power triangle inequality is defined in terms of a function that is herein called the power triangle function. The power triangle function is itself a power mean, and as such is continuous and monotone with respect to its exponential parameter, and also includes the operations of  maximum,  minimum,  mean square,  arithmetic mean, geometric mean, and  harmonic mean as special cases.

scholarly journals Properties of distance spaces with power triangle inequalities

2016 ◽  
Author(s):  
Daniel J Greenhoe
Keyword(s):  
Triangle Inequality ◽  
Metric Spaces ◽  
Geometric Mean ◽  
Power Mean ◽  
Exponential Parameter ◽  
Triangle Function ◽  
Special Cases ◽  
Two Parameter ◽  
Parameter Relation ◽  
Maximum Minimum

Metric spaces provide a framework for analysis and have several very useful properties. Many of these properties follow in part from the triangle inequality. However, there are several applications in which the triangle inequality does not hold but in which we may still like to perform analysis. This paper investigates what happens if the triangle inequality is removed all together, leaving what is called a distance space, and also what happens if the triangle inequality is replaced with a much more general two parameter relation, which is herein called the "power triangle inequality". The power triangle inequality represents an uncountably large class of inequalities, and includes the triangle inequality, relaxed triangle inequality, and inframetric inequality as special cases. The power triangle inequality is defined in terms of a function that is herein called the power triangle function. The power triangle function is itself a power mean, and as such is continuous and monotone with respect to its exponential parameter, and also includes the operations of maximum, minimum, mean square, arithmetic mean, geometric mean, and harmonic mean as special cases.

scholarly journals A fixed point theorem in generalized metric spaces

2013 ◽  
Vol 46 (1) ◽  
Author(s):  
Luljeta Kikina ◽  
Kristaq Kikina
Keyword(s):  
Fixed Point ◽  
Fixed Point Theorem ◽  
Point Theorem ◽  
Metric Space ◽  
Fixed Point Theorems ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Generalized Metric Space ◽  
Generalized Metric Spaces ◽  
Generalized Metric

AbstractA generalized metric space has been defined by Branciari as a metric space in which the triangle inequality is replaced by a more general inequality. Subsequently, some classical metric fixed point theorems have been transferred to such a space. In this paper, we continue in this direction and prove a version of Fisher’s fixed point theorem in generalized metric spaces.

OPTIMAL LOWER BOUND ON THE SUPREMAL STRICT p-NEGATIVE TYPE OF A FINITE METRIC SPACE

2009 ◽  
Vol 80 (3) ◽  
pp. 486-497 ◽  
Author(s):  
ANTHONY WESTON
Keyword(s):  
Lower Bound ◽  
Metric Space ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Elementary Approach ◽  
Negative Type ◽  
Finite Metric Space ◽  
Image Position ◽  
Finite Metric Spaces ◽  
Optimal Lower Bound

AbstractDetermining meaningful lower bounds on the supremal strict p-negative type of classes of finite metric spaces is a difficult nonlinear problem. In this paper we use an elementary approach to obtain the following result: given a finite metric space (X,d) there is a constant ζ>0, dependent only on n=∣X∣ and the scaled diameter 𝔇=(diamX)/min{d(x,y)∣x⁄=y} of X (which we may assume is >1), such that (X,d) has p-negative type for all p∈[0,ζ] and strict p-negative type for all p∈[0,ζ). In fact, we obtain A consideration of basic examples shows that our value of ζ is optimal provided that 𝔇≤2. In other words, for each 𝔇∈(1,2] and natural number n≥3, there exists an n-point metric space of scaled diameter 𝔇 whose supremal strict p-negative type is exactly ζ. The results of this paper hold more generally for all finite semi-metric spaces since the triangle inequality is not used in any of the proofs. Moreover, ζ is always optimal in the case of finite semi-metric spaces.

scholarly journals Unification of the Fixed Point in Integral Type Metric Spaces

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 732 ◽  
Author(s):  
Panda Kumari ◽  
Badriah Alamri ◽  
Nawab Hussain ◽  
Sumit Chandok
Keyword(s):  
Fixed Point ◽  
Metric Space ◽  
Fixed Point Theorems ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Unique Fixed Point ◽  
Fixed Point Theory ◽  
Point Theory ◽  
Integral Type ◽  
Predominant Role

In metric fixed point theory, the conditions like “symmetry” and “triangle inequality” play a predominant role. In this paper, we introduce a new kind of metric space by using symmetry, triangle inequality, and other conditions like self-distances are zero. In this paper, we introduce the weaker forms of integral type metric spaces, thereby we establish the existence of unique fixed point theorems. As usual, illustrations and counter examples are provided wherever necessary.

scholarly journals Some Common Fixed Point Theorems in Partial Metric Spaces

2011 ◽  
Vol 2011 ◽  
pp. 1-16 ◽  
Author(s):  
Erdal Karapınar ◽  
Uğur Yüksel
Keyword(s):  
Fixed Point ◽  
Common Fixed Point ◽  
Fixed Point Theorems ◽  
Triangle Inequality ◽  
Metric Spaces ◽  
Applied Mathematics ◽  
Partial Metric Space ◽  
Partial Metric ◽  
Partial Metric Spaces ◽  
Common Fixed Point Theorems

Many problems in pure and applied mathematics reduce to a problem of common fixed point of some self-mapping operators which are defined on metric spaces. One of the generalizations of metric spaces is the partial metric space in which self-distance of points need not to be zero but the property of symmetric and modified version of triangle inequality is satisfied. In this paper, some well-known results on common fixed point are investigated and generalized to the class of partial metric spaces.

scholarly journals Properties of distance spaces with power triangle inequalities

2016 ◽  
Author(s):  
Daniel J Greenhoe
Keyword(s):  
Triangle Inequality ◽  
Metric Spaces ◽  
Geometric Mean ◽  
Power Mean ◽  
Exponential Parameter ◽  
Triangle Function ◽  
Special Cases ◽  
Two Parameter ◽  
Parameter Relation ◽  
Maximum Minimum

Metric spaces provide a framework for analysis and have several very useful properties. Many of these properties follow in part from the triangle inequality. However, there are several applications in which the triangle inequality does not hold but in which we may still like to perform analysis. This paper investigates what happens if the triangle inequality is removed all together, leaving what is called a distance space, and also what happens if the triangle inequality is replaced with a much more general two parameter relation, which is herein called the "power triangle inequality". The power triangle inequality represents an uncountably large class of inequalities, and includes the triangle inequality, relaxed triangle inequality, and inframetric inequality as special cases. The power triangle inequality is defined in terms of a function that is herein called the power triangle function. The power triangle function is itself a power mean, and as such is continuous and monotone with respect to its exponential parameter, and also includes the operations of maximum, minimum, mean square, arithmetic mean, geometric mean, and harmonic mean as special cases.

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