B-SPLINE FINITE-ELEMENTS AND THEIR EFFICIENCY IN SOLVING RELATIVISTICMEAN-FIELD EQUATIONS

A finite element method using B-splines is presented and compared with a conventional finite element method of Lagrangian type. The efficien cy of both methods has been investigated at the example of a coupled n onlinear system of Dirac eigenvalue equations and inhomogeneous Klein- Gordon equations which describe a nuclear system in the framework of r elativistic mean field theory. Although FEM has been applied with grea t success in nuclear RMF recently, a well known problem is the appeara nce of spurious solutions in the spectra of the Dirac equation. The qu estion whether B-splines lead to a reduction of spurious solutions is analyzed. Numerical expenses, precision and behavior of convergence ar e compared for both methods in view of their use in large scale comput ation on FEM grids with more dimensions. A B-spline version of the obj ect oriented C++ code for spherical nuclei has been used for this inve stigation. (C) 1998 Elsevier Science B.V.