4 papers
Degree-uniform regions for Gautschi's conjecture on subrange Jacobi polynomials
V. Botta, K. Castillo, L. Tertuliano da Silva
Let be the monic polynomial of degree orthogonal on , , with respect to the Jacobi weight , where . Gautschi conjectured that $…
A solution to Meneguette's polynomial problem
K. Castillo
In 1979, Jeltsch [Numer. Math. 32 (1979), 167-181] conjectured that every zero-stable Brown method is stiffly stable. For Brown methods, Meneguette subsequently reduced the…
Yet Another Characterisation of Classical Orthogonal Polynomials?
K. Castillo, G. Gordillo-Núñez
The NIST Handbook of Mathematical Functions (2010) and the NIST Digital Library of Mathematical Functions (2025) classify classical orthogonal polynomials through Bochner's 1929 al…
A Note on the Paper "Localization of Zeros of Polar Polynomials on the Unit Disk"
Renato Alvarez-Nodarse, Kenier Castillo
We show that none of the principal claims of Costas-Santos and Rehouma, Rocky Mountain J. Math. 54 (2024), 995-1004, survives as a new and valid result. The main localisation theor…