Schwinger's Method for the Massive Casimir Effect
  We apply to the massive scalar field a method recently proposed by Schwinger to calculate the Casimir effect. The method is applied with two different regularization schemes: the Schwinger original one by means of Poisson formula and another one by means of analytical continuation. 
M.V. Cougo-Pinto, C. Farina and A.J. Segui-Santonja