Application of the λ-symmetries approach and time independent integral of the modified Emden equation

• Autor(a) principal: Bhuvaneswari, A.
• Data de Publicação: 2012
• Outros Autores: Kraenkel, R. A., Senthilvelan, M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.nonrwa.2011.08.030; http://hdl.handle.net/11449/231278
• topic: λ-symmetries; Integrability; Lie symmetries

In this paper we derive the time-independent integral for a nonlinear dissipative system, namely the modified Emden equation, from Lie point symmetries. We employ the recently introduced λ-symmetries method [C. Muriel, J.L. Romero, First integrals, integrating factors and λ-symmetries of second-order differential equations, J. Phys. A: Math. Theor. 42 (2009) 365207365217] to complete this task. To begin with we recall Lie point symmetries of this system and derive λ-symmetries from the vector fields. The knowledge of λ-symmetries enables us to obtain integrating factors, integrals and the general solution for the linearizable case. While determining the integrating factor from the λ-symmetry for the integrable case we find that this case splits up into three sub-cases. We then obtain the integrating factor and integral for these three sub-cases. The results agree with the ones reported in the literature and thereby give a group theoretical interpretation for the nonstandard time independent integrals exhibited by the system. © 2011 Elsevier Ltd. All rights reserved.