Small-time expansions of the distributions, densities, and option prices of stochastic volatility models with L茅vy jumps
摘要
We consider a stochastic volatility model with L茅vy jumps for a log-return process of the form , where is a classical stochastic volatility process and is an independent L茅vy process with absolutely continuous L茅vy measure . Small-time expansions, of arbitrary polynomial order, in time-, are obtained for the tails , , and for the call-option prices , , assuming smoothness conditions on the density of away from the origin and a small-time large deviation principle on . Our approach allows for a unified treatment of general payoff functions of the form for smooth functions and . As a consequence of our tail expansions, the polynomial expansions in of the transition densities are also obtained under mild conditions.