On log canonical thresholds of reducible plane curves

Abstract

Let f ( x, y ) be an irreducible power series. J. Igusa found a formula for the log canonical threshold of f in terms of the first pair of Puiseux exponents. In this paper, we give an alternate proof for the result, using Shokurov's adjunction theory and the classification of log terminal pairs. The method also gives a generalization of Igusa's result to the case of reducible curves.