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arXiv · 2509.21937

Some stability results for a Fractional Differential Equation with two delays

Pragati Dutta·Sachin Bhalekar
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Abstract

We investigate a nonlinear scalar Caputo fractional delay differential equation with two discrete delays and a delay-dependent feedback coefficient. Under standard Lipschitz assumptions, existence and uniqueness of solutions are established through a fixed-point argument and a fractional Gronwall inequality. The trivial equilibrium is then studied by linearization and characteristic-root analysis. When the first delay is zero, explicit delay-independent stability and instability regions are obtained, together with critical-delay conditions that account for the varying coefficient. When both delays are retained, sufficient parameter conditions for delay-independent stability and instability are derived, and an explicit sufficient threshold for the existence of a positive real characteristic root is obtained. Possible Hopf boundaries are identified through purely imaginary roots and the associated transversality condition. The influence of the fractional order on the spectral conditions is highlighted, and the analytical results are illustrated by numerical simulations and stability diagrams.

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Pragati Dutta, Sachin Bhalekar. 2026-08-14. Some stability results for a Fractional Differential Equation with two delays. https://arxiv.org/abs/2509.21937

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