Taylor expansion of the density in a stochastic heat equation.
The existence of a weak solution and the uniqueness in law are assumed for the equation, the coefficients and being generally -progressive processes. Any weak solution is called a -stock price and Girsanov Theorem jointly with the DDS Theorem on time changed martingales are applied to establish the probability distribution of in in the special case of a diffusion volatility A martingale option pricing method is presented.
This paper continues the research started in [J. Štěpán and P. Dostál: The equation and financial mathematics I. Kybernetika 39 (2003)]. Considering a stock price born by the above semilinear SDE with we suggest two methods how to compute the price of a general option . The first, a more universal one, is based on a Monte Carlo procedure while the second one provides explicit formulas. We in this case need an information on the two dimensional distributions of for where is the exponential...