Hankel Determinant Approach to Generalized Vorob’ev–Yablonski Polynomials and Their Roots

Generalized Vorob’ev–Yablonski polynomials have been introduced by Clarkson and Mansfield in their study of rational solutions of the second Painlevé hierarchy. We present new Hankel determinant identities for the squares of these special polynomials in terms of Schur polynomials. As an application of the identities,
we analyze the roots of generalized Vorob’ev–Yablonski polynomials and provide a
partial characterization for the boundary curves of the highly regular patterns observed numerically in Clarkson and Mansfield (Nonlinearity 16(3):R1–R26, 2003).