Proc Natl Acad Sci U S A. 1972 May;69(5):1271-2. doi: 10.1073/pnas.69.5.1271.
Proceedings of the National Academy of Sciences of the United States of America
E Hille
PMID: 16591989 PMCID: PMC426679 DOI: 10.1073/pnas.69.5.1271
It is known that Emden's equation y'' = x(1-m)y(m) has movable singularities where the solution becomes infinite for one-sided approach. If m = (p + 2)/p, p positive integer, the singularities look like poles of order p. In this note expansions in terms of powers and logarithms are obtained from which the nonpolar nature of these "pseudo-poles" becomes evident. Various extensions are considered. Convergence proofs are deferred to a more detailed publication.