Some Fixed Point Theorems for Expansive Mapping in Extended b-Metric Spaces with Application
Rajesh Kumar Nagwanshee *
Department of Mathematics, Institute for Excellence in Higher Education (IEHE), Bhopal, India.
Manoj Ughade
Department of Mathematics, Institute for Excellence in Higher Education (IEHE), Bhopal, India.
M. S. Chauhan
Department of Mathematics, Institute for Excellence in Higher Education (IEHE), Bhopal, India.
*Author to whom correspondence should be addressed.
Abstract
This study establishes fixed point results for expansive self-maps in complete extended b-metric spaces, where the multiplicative factor in the triangle inequality is governed by a variable control function. Because repeated use of the extended triangle inequality can amplify orbitwise distances, the analysis incorporates an orbit-bound condition, or an analogous summability requirement, to control the distortion generated by backward preimage iterations. Under surjectivity and suitable expansive inequalities, existence and uniqueness results are developed for a single mapping, a two-term condition, a multi-term coefficient condition, and a pair of mappings with a common fixed point. The proofs construct preimage sequences and show geometric decay of successive gaps; completeness then yields convergence, while the expansive conditions establish the fixed-point property and uniqueness. Several examples of extended b-metric spaces are provided to illustrate the framework. A numerical example based on an affine map demonstrates the convergence of the backward sequence towards its analytic fixed point. The manuscript further considers an affine scaling-plus-bias operator in a finite-dimensional setting and relates its equilibrium to the proposed expansive fixed point framework under the stated boundedness, invertibility, and orbit conditions. Overall, the results extend the manuscript’s expansive-mapping analysis from metric and b-metric settings to the extended b-metric setting while retaining explicit control of the variable distortion.
Keywords: Fixed point theorem, expansive mapping, extended b-metric space, surjective operator, nonlinear analysis, iterative methods, application in data normalisation.