X. Carvajal | Searcharxiv

arXiv2024

Global well-posedness for the higher order non-linear Schrödinger equation on modulations spaces

We consider the initial value problem (IVP) associated to a higher order nonlinear Schrödinger (h-NLS) equation $ \partial_{t}u+ia \partial^{2}_{x}u+ b\partial^{3}_{x}u+ic_1|u|^{2}u+c_2 |u|^{2}\partial_{x}u=0, \quad x,t \in \mathbb{R}, $ for given data in the modulation space $M_s^{2,p}(\mathbb{R})$. Using ideias of Killip, Visan, Zhang, Oh, Wang, we prove that the IVP associated to the h-NLS equation is globally well-posed in the modulation spaces $M^{s,p}$ for $s\geq\frac14$ and $p\geq2$.

math.AP↗

arXiv2017

Higher-order Hamiltonian Model for Unidirectional Water Waves

Formally second-order correct, mathematical descriptions of long-crested water waves propagating mainly in one direction are derived. These equations are analogous to the first-order approximations of KdV- or BBM-type. The advantage of these more complex equations is that their solutions corresponding to physically relevant initial perturbations of the rest state may be accurate on a much longer time scale. The initial-value problem for the class of equations that emerges from our derivation is then considered. A local well-posedness theory is straightforwardly established by way of a contraction mapping argument. A subclass of these equations possess a special Hamiltonian structure that implies the local theory can be continued indefinitely.

math.AP↗