2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185498We study the eigenvalues E_{n\ell} of the Salpeter Hamiltonian H = β\sqrt(m^2 + p^2) + vr^2, v>0, β> 0, in three dimensions. By using geometrical arguments we show that, for suitable values of P, here provided, the simple semi-classical formula E = min_{r > 0} {v(P/r)^2 + β\sqrt(m^2 + r^2)} provides both upper and lower energy bounds for all the eigenvalues of the problem.8 pages, 1 figureHigh Energy Physics - TheoryMathematical Physicstext