Time-Independent Schrödinger Equation — David J. Griffiths
Physics — Quantum Mechanics · energy_minimum
Problem
Show that E must exceed the minimum value of V(x), for every normalizable solution to the time-independent Schrödinger equation. What is the classical analog to this statement? Hint: Rewrite Equation 2.5 in the form
dx2d2ψ=ℏ22m[V(x)−E]ψ;
if E<Vmin, then ψ and its second derivative always have the same sign—argue that such a function cannot be normalized.