The open dense conjecture on eventually slow oscillations of the differential equation with delayed negative feedback
Lirui Feng
TL;DR
The paper tackles the open dense conjecture on eventual slow oscillations for the delay differential equation $x'(t) = -\mu x(t) + f(x(t-1))$ under $\mu\ge0$ and $f'<0$, showing that the set of initial data in $X=C[-1,0]$ leading to ES is open and dense. It develops a framework based on strongly order-preserving semiflows with respect to high-rank (specifically, 2-cone) structures, proving invariance and monotonicity properties, a global attractor, and a robust flow-extension on $\omega$-limit sets. A key step is the construction of a complemented 2-cone structure and the SOP dynamics that preserve cones and map certain subsets into their interiors after sufficient time. The main theorem yields the open-dense result for $\mathcal{D}_{ES}$ and, as a corollary, resolves Kaplan and Yorke’s conjecture, providing a rigorous description of the asymptotic behavior of delayed negative-feedback systems with broad implications for the analysis of similar delay equations.
Abstract
In this paper, we show how to use the approach of the strongly order-preserving semiflow with respect to high-rank cones to solve the open dense conjecture on eventually slow oscillations of the differential equation with delayed negative feedback.
