Fractional calculus Bessel-Riesz potentials Cálculo fraccionario Exponential function Fractional derivative Fractional op- erators Función exponencial Generalized Riesz potentials Generalized ultrahyperbolic inverses Hypersingular integral Integral equations K-calculus K-cálculo K-fractional calculus K-gamma function K-mittag-le er function K-mittag-leffer function K-riemann-liouville fractional derivative Marcel Riesz operator Mathematical analysis Miller-ross function Mittag-leffler function P-k-mittag-leffler function Riesz derivatives of order α