arXiv subjects

Lara Sabbagh

Publications and source records attributed to Lara Sabbagh.

3 recordsLinked to original sources

arXiv2015

Oscillatory orbits in the restricted elliptic planar three body problem

The restricted planar elliptic three body problem models the motion of a massless body under the Newtonian gravitational force of the two other bodies, the primaries, which evolve in Keplerian ellipses. A trajectory is called oscillatory if it leaves every bounded region but returns infinitely often to some fixed bounded region. We prove the existence of such type of trajectories for any values for the masses of the primaries provided they make almost circular orbits.

math.DS↗

arXiv2014

Examples of nearly integrable systems on $\mathbb{A}^3$ with asymptotically dense projected orbits

Given an integer $κ\geq2$, we introduce a class of nearly integrable systems on $\mathbb{A}^3$, of the form $$ H_n(θ,r)=\frac12 \Vert r\Vert ^2+\tfrac{1}{n} U(θ_2,θ_3)+f_n(θ,r) $$ where $U\in C^κ(\mathbb{T}^2)$ is a generic potential function and $f_n$ a $C^{κ-1}$ additional perturbation such that $\Vert f_n\Vert_{C^{κ-1}(\mathbb{A}^3)}\leq \tfrac{1}{n}$, so that $H_n$ is a perturbation of the completely integrable system $h(r)=\frac12\Vert r\Vert ^2$. Let $Π:\mathbb{A}^3\to\mathbb{R}^3$ be the canonical projection. We prove that for each $δ>0$, there exists $n_0$ such that for $n\geq n_0$, the system $H_n$ admits an orbit $Γ_n$ at energy $\frac12$ whose projection $Π(Γ_n)$ is $δ$-dense in $Π(H_n^{-1}(\tfrac{1}{2}))$, in the sense that the $δ$-neighborhood of $Π(Γ_n)$ in $\mathbb{R}^3$ covers $Π(H_n^{-1}(\frac{1}{2}))$.

math.DS↗

arXiv2013

An inclination lemma for normally hyperbolic manifolds with an application to diffusion

Let ($M$, $Ω$) be a smooth symplectic manifold and $f:M\rightarrow M$ be a symplectic diffeomorphism of class $C^l$ ($l\geq 3$). Let $N$ be a compact submanifold of $M$ which is boundaryless and normally hyperbolic for $f$. We suppose that $N$ is controllable and that its stable and unstable bundles are trivial. We consider a $C^1$-submanifold $\d$ of $M$ whose dimension is equal to the dimension of a fiber of the unstable bundle of $T_NM$. We suppose that $\d$ transversely intersects the stable manifold of $N$. Then, we prove that for all $\varepsilon>0$, and for $n$ $\in$ $\N$ large enough, there exists $x_n$ $\in$ $N$ such that $f^n(\d)$ is $\varepsilon$-close, in the $C^1$ topology, to the strongly unstable manifold of $x_n$. As an application of this $λ$-lemma, we prove the existence of shadowing orbits for a finite family of invariant minimal sets (for which we do not assume any regularity) contained in a normally hyperbolic manifold and having heteroclinic connections. As a particular case, we recover classical results on the existence of diffusion orbits (Arnold's example).

math.DS↗