Picone identities for half-linear differential equations of fourth order

A class of identities relating Whittaker and Bessel functions

Identities between Whittaker and modified Bessel functions are derived for particular complex orders. Certain polynomials appear in such identities, which satisfy a fourth order differential equation (not of hypergeometric type), and they themselves can be expressed as particular linear combinations of products of modified Bessel and confluent hypergeometric functions.

旧结构，一个消失的公式

Old structures, a vanishing formula

本文针对四阶Hahn差分方程的行列式构造，发现其存在归一化缺陷，通过与Foupouagnigni的方法对比，明确了其在特定正交族上的失效问题及修正方式。