WKB Approximation
- Modern Physics -
Quantum Mechanics Dictionary
Definition
An approximation and alternative-formalism concept defining methods for computing quantum predictions when exact solutions are impractical. It governs controlled expansions, action-based formulations, and phase-space representations that support analytic and numerical work. It does not ensure accuracy outside its regime of validity and requires explicit error assessment or convergence checks.
WKB Approximation
Natural & Formal Sciences Dictionary
Definition
A semiclassical asymptotic method that constructs approximate solutions to linear differential equations with a small parameter multiplying the highest derivative by expanding the logarithm of the solution (the action) in powers of the small parameter.