arXiv subjects
Publications and source records attributed to Liliana Cely.
In this paper, we study the Cauchy problem for a quadratic nonlinear Schrödinger system in dimension six. In~\cite{GaoMengXuZheng}, the authors classified the behavior of solutions under the energy constraint $E(u) < E(Q)$, where $Q$ denotes the ground state. In this work, we classify the dynamics of radial solutions at the threshold energy $E(u) = E(Q)$.
We consider variational and stability properties of a system of two coupled nonlinear Schrödinger equations on the star graph $Γ$ with the $δ$ coupling at the vertex of $Γ$. The first part is devoted to the proof of an existence of the ground state as the minimizer of the constrained energy in the cubic case. This result extends the one obtained recently for the coupled NLS equations on the line. In the second part, we study stability properties of several families of standing waves in the case of a general power nonlinearity. In particular, we study one-component standing waves $e^{iωt}(Φ_1(x), 0)$ and $e^{iωt}(0, Φ_2(x))$. Moreover, we study two-component standing waves $e^{iωt}(Φ(x), Φ(x))$ for the case of power nonlinearity depending on a unique power parameter $p$. To our knowledge, these are the first results on variational and stability properties of coupled NLS equations on graphs.
We study the nonlinear Schrödinger equation with an arbitrary real potential $V(x)\in (L^1+L^\infty)(Γ)$ on a star graph $Γ$. At the vertex an interaction occurs described by the generalized Kirchhoff condition with strength $-γ<0$. We show the existence of ground states $φ_ω(x)$ as minimizers of the action functional on the Nehari manifold under additional negativity and decay conditions on $V(x)$. Moreover, for $V(x)=-\dfracβ{x^α}$, in the supercritical case, we prove that the standing waves $e^{iωt}φ_ω(x)$ are orbitally unstable in $H^{1}(Γ)$ when $ω$ is large enough. Analogous result holds for an arbitrary $γ\in\mathbb{R}$ when the standing waves have symmetric profile.
In this paper, by using a compactness method, we study the Cauchy problem of the logarithmic Schrödinger equation with harmonic potential. We then address the existence of ground states solutions as minimizers of the action on the Nehari manifold. Finally, we explicitly compute ground states (Gausson-type solution) and we show their orbital stability.