Grüss Type Inequalities for Variational Fractional Integral

Abstract

Grüss type inequalities for variational fractional integral with general kernels are established in a rather general form, thus closing the series of papers. Our result includes the corresponding ones in Baleanu et al. (2015), Choi and Purohit (2015), Wang et al. (2014), Tariboon et al. (2014) and Dahmani et al. (2010). Our method is much simpler than those in the literature. Finally, an open problem for further investigations is given.