title: Lagrange-mesh calculations and Fourier transform.
abstract: The Lagrange-mesh method is a very accurate procedure for computing eigenvalues and eigenfunctions of a two-body quantum equation written in the configuration space. Using a Gauss quadrature rule, the method only requires the evaluation of the potential at some mesh points. The eigenfunctions are expanded in terms of regularized Lagrange functions, which vanish at all mesh points except one. Using the peculiarities of the method, it is shown that the Fourier transform of the eigenfunctions, computed in the configuration space, can easily be obtained with good accuracy in the physical domain of the momentum space. Also, observables in this space can easily be computed with good accuracy only using matrix elements and eigenfunctions computed in the configuration space.
authors: Service de Physique Nucléaire et Subnucléaire, Université de Mons-UMONS, Académie universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons, Belgium. gwendolyn.lacroix@umons.ac.be
authors: Gwendolyn
authors: G
authors: Lacroix
authors: Claude
authors: C
authors: Semay