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Existence and conditional energetic stability of three-dimensional fully localised solitary gravity-capillary water waves

Buffoni, B. ; Groves, M. D. ; Sun, S. M. and Wahlén, Erik LU (2013) In Journal of Differential Equations 254(3). p.1006-1096
Abstract
In this paper we show that the hydrodynamic problem for three-dimensional water waves with strong surface-tension effects admits a fully localised solitary wave which decays to the undisturbed state of the water in every horizontal direction. The proof is based upon the classical variational principle that a solitary wave of this type is a critical point of the energy, which is given in dimensionless coordinates by epsilon(eta, phi) = integral(R2){1/2 integral(1+eta)(0) (phi(2)(x) + phi(2)(y) + phi(2)(z))dy +1/2 eta(2) + beta[root 1 + eta(2)(x) + eta(2)(z) - 1]}dxdz, subject to the constraint that the momentum I(eta, phi) = integral(R2)eta(x)phi vertical bar(y=1+eta)dzdz is fixed; here {(x, y, z): x, z is an element of R, y is an element... (More)
In this paper we show that the hydrodynamic problem for three-dimensional water waves with strong surface-tension effects admits a fully localised solitary wave which decays to the undisturbed state of the water in every horizontal direction. The proof is based upon the classical variational principle that a solitary wave of this type is a critical point of the energy, which is given in dimensionless coordinates by epsilon(eta, phi) = integral(R2){1/2 integral(1+eta)(0) (phi(2)(x) + phi(2)(y) + phi(2)(z))dy +1/2 eta(2) + beta[root 1 + eta(2)(x) + eta(2)(z) - 1]}dxdz, subject to the constraint that the momentum I(eta, phi) = integral(R2)eta(x)phi vertical bar(y=1+eta)dzdz is fixed; here {(x, y, z): x, z is an element of R, y is an element of (0, 1 + eta(x, z))} is the fluid domain, phi is the velocity potential and beta > 1/3 is the Bond number. These functionals are studied locally for eta in a neighbourhood of the origin in H-3(R-2). We prove the existence of a minimiser of epsilon subject to the constraint I = 2 mu, where 0 < mu << 1. The existence of a small-amplitude solitary wave is thus assured, and since epsilon and I are both conserved quantities a standard argument may be used to establish the stability of the set D-mu of minimisers as a whole. 'Stability is however understood in a qualified sense due to the lack of a global well-posedness theory for three-dimensional water waves. We show that solutions to the evolutionary problem starting near D-mu remain close to D-mu in a suitably defined energy space over their interval of existence; they may however explode in finite time due to higher-order derivatives becoming unbounded. (C) 2012 Elsevier Inc. All rights reserved. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Differential Equations
volume
254
issue
3
pages
1006 - 1096
publisher
Elsevier
external identifiers
  • wos:000312574500003
  • scopus:84870372052
ISSN
0022-0396
DOI
10.1016/j.jde.2012.10.007
language
English
LU publication?
yes
id
32e9f494-8e57-4d53-9023-5c04afef671b (old id 3400668)
date added to LUP
2016-04-01 11:15:37
date last changed
2022-04-28 08:28:58
@article{32e9f494-8e57-4d53-9023-5c04afef671b,
  abstract     = {{In this paper we show that the hydrodynamic problem for three-dimensional water waves with strong surface-tension effects admits a fully localised solitary wave which decays to the undisturbed state of the water in every horizontal direction. The proof is based upon the classical variational principle that a solitary wave of this type is a critical point of the energy, which is given in dimensionless coordinates by epsilon(eta, phi) = integral(R2){1/2 integral(1+eta)(0) (phi(2)(x) + phi(2)(y) + phi(2)(z))dy +1/2 eta(2) + beta[root 1 + eta(2)(x) + eta(2)(z) - 1]}dxdz, subject to the constraint that the momentum I(eta, phi) = integral(R2)eta(x)phi vertical bar(y=1+eta)dzdz is fixed; here {(x, y, z): x, z is an element of R, y is an element of (0, 1 + eta(x, z))} is the fluid domain, phi is the velocity potential and beta &gt; 1/3 is the Bond number. These functionals are studied locally for eta in a neighbourhood of the origin in H-3(R-2). We prove the existence of a minimiser of epsilon subject to the constraint I = 2 mu, where 0 &lt; mu &lt;&lt; 1. The existence of a small-amplitude solitary wave is thus assured, and since epsilon and I are both conserved quantities a standard argument may be used to establish the stability of the set D-mu of minimisers as a whole. 'Stability is however understood in a qualified sense due to the lack of a global well-posedness theory for three-dimensional water waves. We show that solutions to the evolutionary problem starting near D-mu remain close to D-mu in a suitably defined energy space over their interval of existence; they may however explode in finite time due to higher-order derivatives becoming unbounded. (C) 2012 Elsevier Inc. All rights reserved.}},
  author       = {{Buffoni, B. and Groves, M. D. and Sun, S. M. and Wahlén, Erik}},
  issn         = {{0022-0396}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{1006--1096}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Differential Equations}},
  title        = {{Existence and conditional energetic stability of three-dimensional fully localised solitary gravity-capillary water waves}},
  url          = {{http://dx.doi.org/10.1016/j.jde.2012.10.007}},
  doi          = {{10.1016/j.jde.2012.10.007}},
  volume       = {{254}},
  year         = {{2013}},
}