An alternative Lagrangian approach

In this note, I present alternative expressions for the standard Lagrangian and action, and I discuss the corresponding Hamiltonian and canonical transformation. The new expressions are equivalent to the traditional versions, but written in a way that reveals a useful first-order differential equation for the motion of the system. The conceptual picture of this approach is a phasor diagram, which serves as an alternative to traditional energy bar graph diagrams. This approach works for particles in any one-dimensional potential and for particles in a specific set of separable higher-dimensional potentials.

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Publication Details

Journal
American Journal of Physics
Published
2026-02-19
DOI
https://doi.org/10.1119/5.0307168
Primary Topic
Quantum and Classical Electrodynamics
Type
article
Field-Weighted Citation Impact
0.00
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article

An alternative Lagrangian approach

Keith Zengel
American Journal of Physics
Quantum and Classical Electrodynamics
article

An alternative Lagrangian approach

Keith Zengel
article en

Abstract

In this note, I present alternative expressions for the standard Lagrangian and action, and I discuss the corresponding Hamiltonian and canonical transformation. The new expressions are equivalent to the traditional versions, but written in a way that reveals a useful first-order differential equation for the motion of the system. The conceptual picture of this approach is a phasor diagram, which serves as an alternative to traditional energy bar graph diagrams. This approach works for particles in any one-dimensional potential and for particles in a specific set of separable higher-dimensional potentials.

American Journal of PhysicsVol. 94(3)
Wentworth Institute of Technology (US)
Affordable and clean energy
Openalex Percentile: Top 49%
Quantum and Classical Electrodynamics
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An alternative Lagrangian approach — Keith Zengel · American Journal of Physics (2026) | TGRS Research Map | TGRS