On the continuity of principal eigenvalues for boundary value problems with indefinite weight function with respect to radius of balls in ℝN

Abstract

We investigate the continuity of principal eigenvalues (i.e., eigenvalues corresponding to positive eigenfunctions) for the boundary value problem −Δu(x)=λg(x)u(x), x∈BR(0);u(x)=0, |x|=R, where BR(0) is a ball in ℝN, and g is a smooth function, and we show that λ1+(R) and λ1−(R) are continuous functions of R.