Facultad de Ciencias Naturales y Exactas Universidad del Valle A Note on the Stability and Instability of Travelling Wave of Korteweg-de Vries Type: The Periodic Case José R. Quintero Universidad del Valle Received: July 1, 2010 Accepted: October 6, 2010 Pág. 57-72 Abstract In this paper we adapt the work of M. Grillakis, J. Shatah, and W. Strauss, or J. Bona, P. Souganidis and W. Strauss to the periodic case in spaces having the mean zero property in order to establish the orbital stability/instability of periodic travelling wave solutions of a generalized Korteweg-de Vries type equation. Keywords: KdV type models; periodic travelling waves; orbital stability/instability. MSC (2000): 35Q53, 35B35, 76B30. 1 Introduction It is well known, these models describe the unidirectional propagation of Volumen 14, diciembre 2010 57 Revista de Ciencias 58 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type Volumen 14, diciembre 2010 59 Revista de Ciencias 2 Periodic travelling waves of the generalized KdV type model 60 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type Volumen 14, diciembre 2010 61 Revista de Ciencias 62 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type Volumen 14, diciembre 2010 63 Revista de Ciencias 3 Adaptation of Grillakis, Shatah, Strauss Approach 64 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type Volumen 14, diciembre 2010 65 Revista de Ciencias 66 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type Volumen 14, diciembre 2010 67 Revista de Ciencias 68 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type Volumen 14, diciembre 2010 69 Revista de Ciencias 70 J. R. Quintero A note on the stability and instability of travelling wave of Korteweg-de Vries type References Volumen 14, diciembre 2010 71 Revista de Ciencias Author’s address 72 J. R. Quintero