1. Powers of Catalan generating functions for bounded operators
- Author
-
Miana, Pedro J. and Romero, Natalia
- Subjects
Mathematics - Functional Analysis ,Mathematics - Operator Algebras ,Catalan triangle numbers, generating function, powers of bounded operators, quadratic equation - Abstract
Let $c=(C_n)_{n\ge 0}$ be the Catalan sequence and $T$ a linear and bounded operator on a Banach space $X$ such $4T$ is a power-bounded operator. The Catalan generating function is defined by the following Taylor series, $$ C(T):=\sum_{n=0}^\infty C_nT^n. $$ Note that the operator $C(T)$ is a solution of the quadratic equation $TY^2-Y+I=0.$ In this paper we define powers of the Catalan generating function $C(T)$ in terms of the Catalan triangle numbers. We obtain new formulae which involve Catalan triangle numbers; the spectrum of $c^{\ast j}$ and the expression of $c^{-\ast j}$ for $j\ge 1$ in terms of Catalan polynomials ($\ast$ is the usual convolution product in sequences). In the last section, we give some particular examples to illustrate our results and some ideas to continue this research in the future., Comment: pp 18. arXiv admin note: text overlap with arXiv:2401.16415
- Published
- 2024