An approximate solution for solar and supernova neutrino oscillation in matter

By using Laplace transformation we developed an approximate solution to describe neutrino oscillation probabilities in arbitrary density matter. We show that this approximation solution is valid when matter potential V satisfy $V< \Delta m^2/2E$ and $\int VL<1$, where $L$ is the length of the neutrino oscillation . Thus, the formula is useful for propagation of the solar or supernova neutrinos with terrestrial matter effect.