European Journal of Physics
All roads lead to Schrödinger: projections of the same equation onto different theoretical frameworks of quantum mechanics
J. Oliveira-Cony
Abstract
Abstract Schrödinger’s equation (SE) stands as one of the most recognized formulas in physics, yet its derivation and interpretation vary widely across different theoretical frameworks of quantum mechanics. In this paper, we explore five distinct approaches to obtaining SE: via the optico-mechanical analogy, a group-theoretic method, the action principle (through Hamilton–Jacobi theory and path integrals), stochastic mechanics, and direct postulation. Each derivation is analysed in light of the conceptual foundations it implies, with special attention to how it aligns with the orthodox, realistic, and statistical interpretations of quantum theory. By comparing these frameworks, it is emphasized the interpretative flexibility of SE and the philosophical implications of treating it as a derived versus a postulated equation. This comparison sheds light on the multiplicity of paths that converge on the same mathematical structure, on the particularities of these structures, and on the interpretive tensions that underlie quantum mechanics as a physical theory.