Algebra of Dunkl Laplace-Runge-Lenz vector

Abstract

We consider Dunkl version of Laplace-Runge-Lenz vector associated with a finite Coxeter group $W$ acting geometrically in $\mathbb R^N$ with multiplicity function $g$. This vector generalizes the usual Laplace-Runge-Lenz vector and its components commute with Dunkl-Coulomb Hamiltonian given as Dunkl Laplacian with additional Coulomb potential $\gamma/r$. We study resulting symmetry algebra $R_{g, \gamma}(W)$ and show that it has Poincar\'e-Birkhoff-Witt property. In the absence of Coulomb potential this symmetry algebra $R_{g,0}(W)$ is a subalgebra of the rational Cherednik algebra $H_g(W)$. We show that a central quotient of the algebra $R_{g, \gamma}(W)$ is a quadratic algebras isomorphic to a central quotient of the corresponding Dunkl angular momenta algebra $H_g^{so(N+1)}(W)$. This gives interpretation of the algebra $H_g^{so(N+1)}(W)$ as the hidden symmetry algebra of Dunkl-Coulomb problem in $\mathbb R^N$. By specialising $R_{g, \gamma}(W)$ to $g=0$ we recover a quotient of the universal enveloping algebra $U(so(N+1))$ as the hidden symmetry algebra of Coulomb problem in $\mathbb R^N$. We also apply Dunkl Laplace-Runge-Lenz vector to establish maximal superintegrability of generalised Calogero-Moser systems.