Axially symmetric collapses in the 2-D Benjamin-Ono equation

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Oloo, Joseph O., Shrira, Victor I.
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866916716105170944
author Oloo, Joseph O.
Shrira, Victor I.
author_facet Oloo, Joseph O.
Shrira, Victor I.
contents We study the nonlinear dynamics of localized perturbations within the framework of the essentially two-dimensional generalization of the Benjamin-Ono equation (2D-BO) derived asymptotically from the Navier-Stokes equation. By simulating the 2D-BO equation with the pseudospectral method, we confirm that the localized initial perturbations exceeding a certain threshold collapse, forming a point singularity. Although the 2D-BO equation does not possess axial symmetry, we show that in the vicinity of the collapse singularity, the solution becomes axially-symmetric, whatever its initial shape. We find that perturbations collapse in a self-similar manner, with the perturbation amplitude exploding as $ (\check τ)^{-λ}$ and its transverse scale shrinking as $ (\check τ)^λ$, where $\check τ$ is the time to the moment of singularity. We derive a family of self-similar solutions describing axially symmetric collapses. The value of the free parameter $ λ$ in the self-similar solution is specified by fitting it to the numerical simulation of the initial problem of the evolution of an initially localized perturbation. Remarkably, for the examples we examined the value of the parameter proved to be almost universal: $ λ \approx 0.9$; its dependence on the initial conditions is indiscernible. In the vicinity of the singularity, the dynamics becomes one-dimensional, thus, the derived reduction of the 2D-BO equation provides an effectively one-dimensional model of collapse.
format Preprint
id arxiv_https___arxiv_org_abs_2505_00689
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Axially symmetric collapses in the 2-D Benjamin-Ono equation
Oloo, Joseph O.
Shrira, Victor I.
Mathematical Physics
Pattern Formation and Solitons
14J60, 14F05, 14J26
We study the nonlinear dynamics of localized perturbations within the framework of the essentially two-dimensional generalization of the Benjamin-Ono equation (2D-BO) derived asymptotically from the Navier-Stokes equation. By simulating the 2D-BO equation with the pseudospectral method, we confirm that the localized initial perturbations exceeding a certain threshold collapse, forming a point singularity. Although the 2D-BO equation does not possess axial symmetry, we show that in the vicinity of the collapse singularity, the solution becomes axially-symmetric, whatever its initial shape. We find that perturbations collapse in a self-similar manner, with the perturbation amplitude exploding as $ (\check τ)^{-λ}$ and its transverse scale shrinking as $ (\check τ)^λ$, where $\check τ$ is the time to the moment of singularity. We derive a family of self-similar solutions describing axially symmetric collapses. The value of the free parameter $ λ$ in the self-similar solution is specified by fitting it to the numerical simulation of the initial problem of the evolution of an initially localized perturbation. Remarkably, for the examples we examined the value of the parameter proved to be almost universal: $ λ \approx 0.9$; its dependence on the initial conditions is indiscernible. In the vicinity of the singularity, the dynamics becomes one-dimensional, thus, the derived reduction of the 2D-BO equation provides an effectively one-dimensional model of collapse.
title Axially symmetric collapses in the 2-D Benjamin-Ono equation
topic Mathematical Physics
Pattern Formation and Solitons
14J60, 14F05, 14J26
url https://arxiv.org/abs/2505.00689