Abstract:
We construct and justify rigorously the complete asymptotic expansion for the electric resistance of a three-dimensional resistance connected by two small contacts of arbitrary shape. We obtain explicit formulae for the first two terms in the asymptotics generalized the classical Helm formula of one-term asymptotics for two small round contacts of same radius.
Keywords:electrical resistance, small contacts, Helm formula, asymptotic expansion, boundary value problem, the method of matching asymptotic expansions, Laplace equation, mixed problem.