Existence of Minimizers for Fractional Variational Problems Containing Caputo Derivatives

We study dynamic minimization problems of the calculus of variations with Lagrangian functionals containing Riemann-Liouville fractional integrals, classical and Caputo fractional derivatives. Under assumptions of regularity, coercivity and convexity, we prove existence of solutions.
Comment: This is a preprint of a paper whose final and definite form will be published in: Adv. Dyn. Syst. Appl. Submitted July 31, 2012; revised and accepted August 11, 2012