“…The more general Fenichel theory of persistence of normally hyperbolic invariant manifolds 20,21 guarantees the persistence of these manifolds for sufficiently small e. In particular, we use the Fenichel theory presented in Ref. 35 to conclude that the full system possesses invariant manifolds, which we also label S e a;2 and S e r;2 , that are differentiably OðeÞ close to their unperturbed counterparts. Of course, in this regime, the dynamics in the h direction is fast and the dynamics in the z direction is slow.…”
Section: The Main Third-order System and Its Torus Canardsmentioning
confidence: 98%
“…In the remainder of this section, we briefly examine how these manifolds persist for 0 < e ( 1, using Fenichel theory, 21,34 following in particular the presentation of Ref. 35. We exclude small neighborhoods of the ring C SN and the point P 0 , where the manifolds are not normally hyperbolic.…”
Section: The Main Third-order System and Its Torus Canardsmentioning
We study the recently observed phenomena of torus canards. These are a higher-dimensional generalization of the classical canard orbits familiar from planar systems and arise in fast-slow systems of ordinary differential equations in which the fast subsystem contains a saddle-node bifurcation of limit cycles. Torus canards are trajectories that pass near the saddle-node and subsequently spend long times near a repelling branch of slowly varying limit cycles. In this article, we carry out a study of torus canards in an elementary third-order system that consists of a rotated planar system of van der Pol type in which the rotational symmetry is broken by including a phase-dependent term in the slow component of the vector field. In the regime of fast rotation, the torus canards behave much like their planar counterparts. In the regime of slow rotation, the phase dependence creates rich torus canard dynamics and dynamics of mixed mode type. The results of this elementary model provide insight into the torus canards observed in a higher-dimensional neuroscience model.
“…The more general Fenichel theory of persistence of normally hyperbolic invariant manifolds 20,21 guarantees the persistence of these manifolds for sufficiently small e. In particular, we use the Fenichel theory presented in Ref. 35 to conclude that the full system possesses invariant manifolds, which we also label S e a;2 and S e r;2 , that are differentiably OðeÞ close to their unperturbed counterparts. Of course, in this regime, the dynamics in the h direction is fast and the dynamics in the z direction is slow.…”
Section: The Main Third-order System and Its Torus Canardsmentioning
confidence: 98%
“…In the remainder of this section, we briefly examine how these manifolds persist for 0 < e ( 1, using Fenichel theory, 21,34 following in particular the presentation of Ref. 35. We exclude small neighborhoods of the ring C SN and the point P 0 , where the manifolds are not normally hyperbolic.…”
Section: The Main Third-order System and Its Torus Canardsmentioning
We study the recently observed phenomena of torus canards. These are a higher-dimensional generalization of the classical canard orbits familiar from planar systems and arise in fast-slow systems of ordinary differential equations in which the fast subsystem contains a saddle-node bifurcation of limit cycles. Torus canards are trajectories that pass near the saddle-node and subsequently spend long times near a repelling branch of slowly varying limit cycles. In this article, we carry out a study of torus canards in an elementary third-order system that consists of a rotated planar system of van der Pol type in which the rotational symmetry is broken by including a phase-dependent term in the slow component of the vector field. In the regime of fast rotation, the torus canards behave much like their planar counterparts. In the regime of slow rotation, the phase dependence creates rich torus canard dynamics and dynamics of mixed mode type. The results of this elementary model provide insight into the torus canards observed in a higher-dimensional neuroscience model.
“…Taking into account that f n vanishes at τ = 0, σ = 0 [see (46)], we obtain f n ≤ C τ, σ ≤ Cλ k J due to (55) and (58). Combining these inequalities, we find that…”
Section: Lemma 2 Given Any Sufficiently Largek γ and D For Any Shamentioning
confidence: 79%
“…The straightening of the manifolds and foliations means that one can introduce C 1 -coordinates (u, v, z) in a neighbourhood of A such that the manifold W s loc will have equation z = 0, the manifold W u loc will be given by u = 0, and the leaves of the foliations E ss and E uu will all have the form {z = 0, v = const} and {u = 0, v = const} respectively (cf. [58]). The cylinder A thus lies in {u = 0, z = 0}.…”
Section: Fenichel Coordinates Cross Form Of the Map And Estimates Fmentioning
Abstract:We assume that a symplectic real-analytic map has an invariant normally hyperbolic cylinder and an associated transverse homoclinic cylinder. We prove that generically in the real-analytic category the boundaries of the invariant cylinder are connected by trajectories of the map.
“…It was first proved by Jones and Kopell [15] and extended to more general settings by many authors [14,16,13,[19][20][21][22]4,5]. There are basically three approaches to the proof and we refer to [21] for detailed explanations.…”
We prove the existence of families of random invariant manifolds for singularly perturbed systems of ordinary differential equations with sufficiently small real noise. We use these invariant manifolds to prove a random version of the inclination theorem or exchange lemma. Published by Elsevier Inc.
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