AUTHOR=Kumar Sachin , Baleanu Dumitru TITLE=A New Numerical Method for Time Fractional Non-linear Sharma-Tasso-Oliver Equation and Klein-Gordon Equation With Exponential Kernel Law JOURNAL=Frontiers in Physics VOLUME=Volume 8 - 2020 YEAR=2020 URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2020.00136 DOI=10.3389/fphy.2020.00136 ISSN=2296-424X ABSTRACT=In this work, we derived a novel numerical scheme to find out the numerical solution of fractional PDEs having Caputo-Fabrizio (C-F) fractional derivatives. We first find out the formula of approximation for the C-F derivative of the function f(t)=t^k. We approximate the C-F derivative in time direction with the help of the Legendre spectral method and approximation formula of t^k. The unknown function and their derivatives in spatial direction are approximated with the help of the method which is based on a quasi wavelet. We implement this newly derived method to solve the non-linear Sharma-Tasso-Oliver equation and non-linear Klein-Gordon equation in which time-fractional derivative is of C-F type. The accuracy and validity of this new method are depicted by giving the numerical solution of some numerical examples. The numerical results for the particular cases of Klein-Gordon equation are compared with the existing exact solutions and from the obtained error we can conclude that our proposed numerical method achieves accurate results. The effect of time-fractional exponent $\alpha$ on the solution profile is characterized by Figures. The comparison of solution profile u(x,t) for different type time