Benjamin–Bona–Mahony Equation with Variable Coefficients: Conservation Laws

Symmetry

Ben Muatjetjeja¹ 

[1] International Institute for Symmetry Analysis and Mathematical Modelling, Department of Mathematical Sciences, North-West University, Mafikeng Campus, Private Bag X 2046, Mmabatho 2735, South Africa; E-Mail

关键词: Benjamin–Bona–Mahony equation with variable coefficients;    lagrangian;    noether operators;    conservation laws;   

DOI  :  10.3390/sym6041026

来源: mdpi

【 摘 要 】

This paper aims to construct conservation laws for a Benjamin–Bona–Mahony equation with variable coefficients, which is a third-order partial differential equation. This equation does not have a Lagrangian and so we transform it to a fourth-order partial differential equation, which has a Lagrangian. The Noether approach is then employed to construct the conservation laws. It so happens that the derived conserved quantities fail to satisfy the divergence criterion and so one needs to make adjustments to the derived conserved quantities in order to satisfy the divergence condition. The conservation laws are then expressed in the original variable. Finally, a conservation law is used to obtain exact solution of a special case of the Benjamin–Bona–Mahony equation.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland