196,665 research outputs found
Partial b_{v}(s) and b_{v}({\theta}) metric spaces and related fixed point theorems
In this paper, we introduced two new generalized metric spaces called partial
b_{v}(s) and b_{v}({\theta}) metric spaces which extend b_{v}(s) metric space,
b-metric space, rectangular metric space, v-generalized metric space, partial
metric space, partial b-metric space, partial rectangular b-metric space and so
on. We proved some famous theorems such as Banach, Kannan and Reich fixed point
theorems in these spaces. Also, we give definition of partial v-generalized
metric space and show that these fixed point theorems are valid in this space.
We also give numerical examples to support our definitions. Our results
generalize several corresponding results in literature.Comment: 15 page
Topology from enrichment: the curious case of partial metrics
For any small quantaloid \Q, there is a new quantaloid \D(\Q) of
diagonals in \Q. If \Q is divisible then so is \D(\Q) (and vice versa),
and then it is particularly interesting to compare categories enriched in \Q
with categories enriched in \D(\Q). Taking Lawvere's quantale of extended
positive real numbers as base quantale, \Q-categories are generalised metric
spaces, and \D(\Q)-categories are generalised partial metric spaces, i.e.\
metric spaces in which self-distance need not be zero and with a suitably
modified triangular inequality. We show how every small quantaloid-enriched
category has a canonical closure operator on its set of objects: this makes for
a functor from quantaloid-enriched categories to closure spaces. Under mild
necessary-and-sufficient conditions on the base quantaloid, this functor lands
in the category of topological spaces; and an involutive quantaloid is
Cauchy-bilateral (a property discovered earlier in the context of distributive
laws) if and only if the closure on any enriched category is identical to the
closure on its symmetrisation. As this now applies to metric spaces and partial
metric spaces alike, we demonstrate how these general categorical constructions
produce the "correct" definitions of convergence and Cauchyness of sequences in
generalised partial metric spaces. Finally we describe the Cauchy-completion,
the Hausdorff contruction and exponentiability of a partial metric space, again
by application of general quantaloid-enriched category theory.Comment: Apart from some minor corrections, this second version contains a
revised section on Cauchy sequences in a partial metric spac
Partial metric spaces with negative distances and fixed point theorems
In this paper we consider partial metric spaces in the sense of O'Neill. We
introduce the notions of strong partial metric spaces and Cauchy functions. We
prove a fixed point theorem for such spaces and functions that improves
Matthews' contraction mapping theorem in two ways. First, the existence of
fixed points now holds for a wider class of functions and spaces. Second, our
theorem also allows for fixed points with nonzero self-distances. We also prove
fixed point theorems for orbitally -contractive and orbitally
-contractive maps. We then apply our results to give alternative proofs
of some of the other known fixed point theorems in the context of partial
metric spaces.Comment: 19 page
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