An analysis of double power series using rotationally covariant approximants

摘要

Using rotationally covariant approximants developed at Canterbury we examine double power series corresponding to functions with singularities of the form [x − xS (y)]−γ, where xS(y) is linear in y. Our interest is ino(i)the capacity of these approximants to reproduce the locus of singularities and exponents of these functions, and(ii)the accuracy of this analysis compared with that using approximants which are covariant under relative scale changes, but not under rotations.