Asymptotic behavior for the free boundary of parabolic variational inequalities and applications to sequential analysis

Abstract

We consider a solution of a parabolic variational inequality in one space variable. The obstacle is the minimum of two functions, and the inhomogeneous term has a singularity as $t \downarrow 0$. It is shown that the free boundary consists of two curves initiating at a point on $t=0$; their behavior as $t \downarrow 0$ is studied. An application is given to problems in sequential analysis with two or three hypotheses.