2411.01181
On the dynamics of non-autonomous systems in a neighborhood of a homoclinic trajectory
A. Calamai, M. Franca, M. Pospíšil
correctmedium confidence
- Category
- Not specified
- Journal tier
- Specialist/Solid
- Processed
- Sep 28, 2025, 12:56 AM
- arXiv Links
- Abstract ↗PDF ↗
Audit review
The paper rigorously proves Theorems 4.2 and 4.3—existence/regularity of forward/backward Poincaré maps and sharp power-law/log-time estimates—under F0–F2, K, G, by constructing barrier curves, using exponential dichotomy, and a sequence of fixed-point and comparison arguments; see the theorem statements and definitions of the exponents σ and Σ (Theorem 4.2, Theorem 4.3, and (2.9)) . The Cr nature of the event times and maps follows from the flow smoothness and an implicit-function argument around the transversal crossings (Lemma 3.6 and Remark 3.7) . The proofs in §5 rely on robust exponential dichotomy and carefully controlled estimates across the four subpaths of the loop, culminating in the stated bounds . The candidate model gives a different but standard approach: nonautonomous Hadamard–Perron, implicit-function theorem for event times, Dulac-type estimates on each side, and composition; it recovers exactly the same exponents (including Σfwd = Σfwd+ + σfwd+/λ−u) and the trajectory–trajectory bounds via a terminal-value variation-of-constants estimate. Minor omissions in the model (notably the barrier-set machinery and parameter-order bookkeeping ϖ,β,δ,µ used in the paper) do not affect correctness. Hence both are correct, with substantially different proof strategies.
Referee report (LaTeX)
\textbf{Recommendation:} minor revisions \textbf{Journal Tier:} specialist/solid \textbf{Justification:} The manuscript establishes precise nonautonomous Poincaré return estimates near a homoclinic loop for planar piecewise-smooth systems without sliding near the equilibrium. The results (Theorems 4.2 and 4.3) are technically solid and likely useful for subsequent work on chaotic dynamics (e.g., Melnikov-type results) in discontinuous systems. The exposition is careful but lengthy, and the parameter bookkeeping (β, ϖ, δ, μ) could be streamlined. Clarifying the dependence on the nonautonomous stable-manifold framework and offering a short road-map for the multi-step proof would improve readability.