2 papers
math.CA2026
Half-Step-Invariant Sets, Admissible Maps, and Classical Orthogonal Polynomials
K. Castillo
This paper revisits the notion of classical orthogonal polynomials from a broader functional-analytic point of view. It is intended neither as a survey of known results nor as a re…
math.CA2025
A note on lower bounds for numerical series
R. Ãlvarez-Nodarse, K. Castillo
After passage to the representing measure, the three principal theorems of Esstafa and Sfaxi, J. Math. Anal. Appl. 556 (2026), 130199, reduce respectively to Jensen's inequality, o…