Before revision:  The results of this paper generalize the ones obtained in \mbox{%DIFAUXCMD FFF ,  Short maturity asymptotic for a fast mean reverting Heston stochastic volatility model , SIAM Journal on Financial Mathematics, Vol  . 1 , 2010)  by a moment generating function computation in the particular case of the Heston model.
After revision:  The results of this paper generalize the ones obtained in \mbox{%DIFAUXCMD FFF ,  , SIAM Journal on Financial Mathematics, Vol . 1 , 2010) by a moment generating function computation in the particular case of the Heston model.