2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67833Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider an ordered pair of linear transformations $A:V\to V$ and $A^*:V\to V$ that satisfy conditions (i), (ii) below. (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal and the matrix representing $A^*$ is irreducible tridiagonal. We call such a pair a {\it Leonard pair} on $V$. Let $A,A^*$ denote a Leonard pair on $V$. There exists a decomposition of $V$ into a direct sum of 1-dimensional subspaces, with respect to which $A$ is lower bidiagonal and $A^*$ is upper bidiagonal. This is known as the {\it split decomposition}. We use the split decomposition to obtain several characterizations of Leonard pairs.18 pagesRings and AlgebrasQuantum AlgebraRepresentation Theory05E35, 05E30, 33C45, 33D45Two linear transformations each tridiagonal with respect to an eigenbasis of the other; comments on the split decompositiontext