Volume 21, Number 1  (2026)

CONTENTS

On the Homogeneous Quadratic Diophantine Equation x² + y²=(p²+q²)z²; p, q are Prime Numbers
pp.1-6
Dr. Smiti Aggarwal

Discrete-Time Dynamical Models for Population Growth and Species Interaction
Dr. Elena Markovic

Fixed-Point Methods for Nonlinear Difference Equations and Their Applications
Dr. Weihao Chen and Dr. Mingyu Luo

Global Stability of Discrete Epidemic Models with Time-Dependent Parameters
Dr. Hiroshi Fujita and Dr. Aiko Tanaka

Numerical Stability of Discretized Dynamical Systems with Delayed Feedback
Dr. Min-Seok Choi and Dr. Eun-Ji Han

Fractional Difference Equations: Theory, Stability, and Applications
Dr. Ahmed Al-Mansouri and Dr. Salma Al-Hadidi

Discrete Dynamical Models for Renewable Energy Resource Management
Dr. Carlos Ferreira and Dr. Beatriz Mendes

Periodic Solutions of Nonlinear Difference Equations Arising in Mathematical Biology
Dr. Natalia Petrova and Dr. Dmitri Volkov