Bulletin of the
Korean Mathematical Society BKMS

This minipaper offers a formula which is dual to that of Viskov \cite{vis}. While Viskov's can be thought of as a rising formula for Laguerre polynomials, ours is precisely the lowering one. Besides documenting the formula, which seems to be missing, we want to provide a (rather elementary) operator theory argument instead of making crude calculations. In other words, the annihilation and creation {\it operators} are confronted with lowering and rising {\it formulae}; they are often failed to be distinguished.

Keywords: Laguerre polynomials, raising and lowering formulae, weighted shift operator

MSC numbers: Primary 33C45; Secondary 47A05