A fractional analog of Duhamel's principle
  The well known Duhamel's principle allows to reduce the Cauchy problem for linear inhomogeneous partial differential equations to the Cauchy problem for the corresponding homogeneous equation. In the paper one of the possible generalizations of the classical Duhamel's principle to the time-fractional pseudo-differential equations is established. 
Sabir Umarov and Erkin Saydamatov