Nevanlinna functions with real zeros

A. Eremenko, S. Merenkov
2005 Illinois Journal of Mathematics  
We show that for every non-negative integer d, there exist differential equations w + P w = 0, where P is a polynomial of degree d, such that some non-trivial solution w has all roots real.
doi:10.1215/ijm/1258138128 fatcat:c6qtf2kdnzfq3edwrswhxbhhlq