Results 81 to 90 of about 339 (176)

On generalizations of some fixed point theorems in semimetric spaces with triangle functions

Frontiers in Applied Mathematics and Statistics
In the present study, we prove generalizations of Banach, Kannan, Chatterjea, Ćirić-Reich-Rus fixed point theorems, as well as of the fixed point theorem for mapping contracting perimeters of triangles.
Evgeniy Petrov, Ruslan Salimov, Ravindra K. Bisht   +2 more
doaj   +1 more source

Totally bounded ultrametric spaces generated by labeled rays

Applied General Topology
We will say that a tree T is almost a ray if T is the union of a ray and a finite tree. Let l be a non-degenerate labeling of the vertex set V of almost a ray T and let dI be the corresponding ultrametric on V.
Oleksiy Dovgoshey, Valentino Vito
doaj   +1 more source

Ultrametricity increases the predictability of cultural dynamics

New Journal of Physics, 2018
A quantitative understanding of societies requires useful combinations of empirical data and mathematical models. Models of cultural dynamics aim at explaining the emergence of culturally homogeneous groups through social influence.
Alexandru-Ionuţ Băbeanu, Jorinde van de Vis, Diego Garlaschelli   +2 more
doaj   +1 more source

Multi-Metric φ-Contractions on Quadrilaterals with Applications to Fractional Boundary-Value Problems

Mathematics
In this paper, we introduce a general class of quadrilateral total pairwise φ-contractions and investigate fixed-point results for such mappings in metric and semimetric spaces endowed with multiple distinct metrics.
Ravindra K. Bisht, Manuel De La Sen
doaj   +1 more source

Ultrametric Fredholm operators and approximate pseudospectrum [PDF]

Arab Journal of Mathematical Sciences
PurposeThe paper deals with ultrametric bounded Fredholm operators and approximate pseudospectra of closed and densely defined (resp. bounded) linear operators on ultrametric Banach spaces.Design/methodology/approachThe author used the notions of ...
Jawad Ettayb
doaj   +1 more source

A GEOMETRIC STUDY OF WASSERSTEIN SPACES: ULTRAMETRICS [PDF]

Mathematika, 2014
We study the geometry of the space of measures of a compact ultrametric space X, endowed with the L^p Wasserstein distance from optimal transportation. We show that the power p of this distance makes this Wasserstein space affinely isometric to a convex subset of l^1.
openaire   +4 more sources

Fixed Point Results of Miculescu-Mihail, Mitrović-Hussain, and Boyd-Wong Type in Regular Semimetric Spaces

Journal of Mathematics
We establish three types of nonlinear fixed point theorems in regular semimetric spaces. First, we generalize Miculescu and Mihail’s result, thereby unifying the Matkowski fixed point theorem and the Istrăţescu fixed point theorem concerning convex ...
Shu-Min Lu, Peng Wang, Fei He
doaj   +1 more source

Non-ultrametric phylogenetic trees shed new light on Neanderthal introgression. [PDF]

Org Divers Evol, 2023
Tozzi A.
europepmc   +1 more source

Center of Distances of Ultrametric Spaces Generated by Labeled Trees

Mathematics
The center of distances of a metric space (X,d) is the set C(X) of all t∈R+ for which the equation d(x,p)=t has a solution for each p∈X. We prove that the equalities C(X)={0} or C(X)={0,diamX} hold if (X,d) is an ultrametric space generated by labeled ...
Oleksiy Dovgoshey, Olga Rovenska
doaj   +1 more source

A p-Adic Model of Quantum States and the p-Adic Qubit. [PDF]

Entropy (Basel), 2022
Aniello P, Mancini S, Parisi V.
europepmc   +1 more source