Strong stability preserving properties of composition Runge-Kutta schemes

In this paper Strong Stability Preserving (SSP) properties of Runge Kutta methods obtained by com- posing k different schemes with different step sizes are studied. The SSP coefficient of the composition method is obtained and an upper bound on this coefficient is given. Some examples are shown. In par- ticular, it is proven that the optimal n2-stage third order explicit Runge-Kutta methods obtained by D.I. Ketcheson [SIAM J. Sci. Comput. 30(4), 2008] are composition of first order SSP schemes.Supported by Ministerio de Economía y Competividad (Spain), Project MTM2016-77735-C3-2-