Electronic Journal of Differential Equations, Vol. 2011 (2011), No. 149, pp. 1-16. Title: Ott-Sudan-Ostrovskiy equations on a right half-line Authors: Martin P. Arciga-Alejandre (UMSNH, Morelia, Michoacan, Mexico) Elena I. Kaikina (UMSNH, Morelia, Michoacan, Mexico) Abstract: We consider initial-boundary value problems for the Ott-Sudan-Ostrovskiy equation on a right half-line. We show the the existence of solutions, global in time, and study their asymptotic behavior for large time. Submitted August 8, 2011. Published November 03, 2011. Math Subject Classifications: 35Q35. Key Words: Dispersive nonlinear evolution equation; asymptotic behavior; Initial-boundary value problem.