## Lie symmetry analysis of differential equations in finance.(English)Zbl 0929.35006

The Black-Schole equation $$u_t+\frac{1}{2} A^2x^2u_{xx}+ Bxu_x-Cu=0$$ and Jacobs-Jones equation $$u_t=\frac{1}{2} A^2x^2u_{xx}+ ABCxyu_{xy}+ \frac{1}{2}B^2y^2u_{yy} +(Dx\ln\frac{y}{x}- Ex^{3/2})u_x+ (Fy\ln\frac{G}{y}- Hyx^{1/2})u_y-xu$$ are investigated in this paper. For the equations, algebras of classical symmetries are calculated; particular solutions are found with the help of symmetries. The most general transformation of the Black-Schole equation to the heat equation is obtained. The fundamental solution of the Cauchy problem for this equation is found.

### MSC:

 35A30 Geometric theory, characteristics, transformations in context of PDEs 91B24 Microeconomic theory (price theory and economic markets) 58J70 Invariance and symmetry properties for PDEs on manifolds
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