We study the asymptotic behaviour of the principal eigenvalue of a Robin (or
generalised Neumann) problem with a large parameter in the boundary condition
for the Laplacian in a piecewise smooth domain. We show that the leading
asymptotic term depends only on the singularities of the boundary of the
domain, and give either explicit expressions or two-sided estimates for this
term in a variety of situations.Comment: 16 pages; no figures; replaces math.SP/0403179; completely re-writte
