Estimating ground-state energies in supersymmetric quantum mechanics. Pt. 1

For a class of the dynamically broken supersymmetric quantum-mechanical models proposed by Witten, we examine various methods of estimating the ground-state energy, including the instanton method developed by Salomonson and van Holten. We show that no existing method is entirely satisfactory, and developed a method using all stationary points of the Schroedinger potential (including those in the complex plane) in conjunction with the Rayleigh-Ritz variational method, thus combining perturbative and nonperturbative effects. Generalisations to more than one degree of freedom and to field theory are discussed. (orig.)