We study the structure of solutions of the one-dimensional non-linear
pseudodifferential equation describing the dynamics of the p-adic open string
for the scalar tachyon field p21∂t2Φ=Φp. We elicit
the role of real zeros of the entire function Φp(z) and the behaviour of
solutions Φ(t) in the neighbourhood of these zeros. We point out that
discontinuous solutions can appear if p is even. We use the method of
expanding the solution Φ and the function Φp in the Hermite
polynomials and modified Hermite polynomials and establish a connection between
the coefficients of these expansions (integral conservation laws). For p=2 we
construct an infinite system of non-linear equations in the unknown Hermite
coefficients and study its structure. We consider the 3-approximation. We
indicate a connection between the problems stated and the non-linear
boundary-value problem for the heat equation.Comment: AMSTeX, 26 page