Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

International Journal of Geometric Methods in Modern Physics

Deriving the generalized momentum operators from covariant derivatives

Mehdi Jafari Matehkolaee

Published Jul 20, 2023• 1 citation
Publisher

Abstract

The generalized momentum operators are derived in the framework of non-relativistic quantum mechanics, taking into account an especial assumption on the covariant derivative. According to this assumption, a scalar density doesn’t change under the action of covariant derivative. The Hermitian form of the covariant derivative is discussed. It is shown that, with the help of the adjoint of covariant derivatives, generalized momentum operators can be derived. The inverse of covariant derivative is calculated. It is shown that the inverse of generalized momentum operators can be deduced from the inverse of covariant derivatives.

DOI
10.1142/s0219887823502316

Related papers

Hermiticity and Self-Adjointness in Quantum Mechanics

Alexander J. Silenko

Hamiltonians in the geveralized Feshbach-Villars and Foldy-Wouthuysen representations describing an interaction of a scalar particle with electromagnetic fields in the Minkowski spacetime are self-adjoint and Hermitian (or pseudo-Hermitian) when they are presented in terms of operators of covariant derivatives. When one uses curvilinear coordinates in special relativity, the transition to the canonical momentum operator does not change these properties. When the curvilinear coordinates are applied in general relativity, the corresponding transition to the canonical momentum operator leads to the seeming non- Hermiticity of the Hamiltonians. Since the Hamiltonians remain in fact Hermitian, this seeming non-Hermiticity should not be eliminated by any nonunitary transformation.

Nonlinear Phenomena in Complex Systems•Apr 2, 2021•1 citation

Covariant relativistic quantum theory

Theodore Garavaglia

Covariant classical particle dynamics is described, and the associated covariant relativistic particle quantum mechanics is derived. The invariant symmetric bracket is defined on the space of quantum amplitudes, and its relation to a generalized Hamiltonian dynamics and to a covariant Schrödinger type equation is shown. Examples for relativistic potential problems are solved. Mathematically and physically acceptable probability densities for the Klein-Gordon equation and for the Dirac equation are derived, and a new continuity equation for each case is given. The quantum distribution for mass is discussed, and unambiguous representations of four-velocity and four-acceleration operators are given.

arXiv:hep-th/0011180•Nov 20, 2000•1 citation

Generalized momentum operators from Fourier transform correspondence

Siddharth Dwivedi

In this work we take a closer look at the algebraic-operator correspondence between the momentum space and the position space which defines the form of the canonical momentum operator in position space in Quantum Mechanics (QM). Starting from the Fourier transform (FT) relationship, we present a Hermitian generalization of the canonical momentum operator in position space. The action of the generalized operator is found to generate a local flow accompanied by position-dependent rescaling, rather than a global translation. Explicit eigenfunctions are obtained for representative cases and are shown to possess a well-defined limit to the plane-wave solution in QM. As an illustration, the infinite square well problem is solved using the generalized operator, yielding a deformed spectrum that has a smooth limit to the standard QM result.

arXiv:2506.10950•Jun 12, 2025•0 citations

Quantum mechanical momentum operators and Hamilton’s variational principle

Kenneth R. Brownstein

The Euler–Lagrange equations in classical field theory are not covariant with respect to a transformation of independent variables. A modified covariant version of these equations is presented. The modification consists of replacing the partial derivative ∂/∂qi by the Hermitian quantum mechanical momentum operator pi conjugate to the coordinate qi. This momentum operator is given by pi=−ih/[∂/∂qi+(1/2) ∂/∂qi(lnJ)], where J is the Jacobian of the transformation.

American Journal of Physics•Jul 1, 1976•10 citations

The G-dynamics of the QCPB theory

Gen Wang

In this paper, we further study the G-dynamics newly emerged in the covariant dynamics defined by the QCPB theory. Then we want to seek the precise formulations of the G-dynamics to calculate the practical quantum problems. We explicitly verify how the role of G-dynamics plays in quantum mechanics, and then we propose three new operators based on the G-dynamics: D-operator, T-operator and G-operator, we find that the non-Hermitian operators are inevitable to appear in the framework of the QCPB. Then the eigenvalue equation of them are discussed accordingly by using the Schrodinger equation and geometrinetic energy operator (GEO) which leads to the Ri-operator, respectively, we obtain some useful results between two quantum situations. Meanwhile, we present generalized covariant wave equation based on the G-operator. The GEO for quantum harmonic oscillator as an application is further calculated.

•Mar 31, 2020•1 citation

Derivation of the coordinate-momentum commutation relations from canonical invariance

Moshe Shapiro

Based on (i) the spectral resolution definition of the momentum operator, (ii) the linearity of correspondence between physical observables and quantum Hermitian operators, (iii) the definition of conjugate coordinate-momentum variables in classical mechanics, and (iv) the invariance of the classical Hamiltonian to canonical transformations (transformations that change from one set of conjugate variables to another), we show that the $[\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{x},\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{p}]$ coordinate-momentum commutator must have the value $ih$ where $h$ is a real nonzero number (which we can identify with the experimentally determined $\ensuremath{\hbar}$). The results are then extended to include all generalized coordinates and their conjugate momenta as well as the Cartesian special-relativistic case.

Physical Review A•Oct 31, 2006•5 citations
The generalized momentum operators are derived in the framework of non-relativistic quantum mechanics, taking into account an especial assumption on the covariant derivative. According to this assumption, a scalar density doesn’t change under the action of covariant derivative. The Hermitian form of the covariant derivative is discussed. It is shown that, with the help of the adjoint of covariant derivatives, generalized momentum operators can be derived. The inverse of covariant derivative is calculated. It is shown that the inverse of generalized momentum operators can be deduced from the inverse of covariant derivatives.
Hamiltonians in the geveralized Feshbach-Villars and Foldy-Wouthuysen representations describing an interaction of a scalar particle with electromagnetic fields in the Minkowski spacetime are self-adjoint and Hermitian (or pseudo-Hermitian) when they are presented in terms of operators of covariant derivatives. When one uses curvilinear coordinates in special relativity, the transition to the canonical momentum operator does not change these properties. When the curvilinear coordinates are applied in general relativity, the corresponding transition to the canonical momentum operator leads to the seeming non- Hermiticity of the Hamiltonians. Since the Hamiltonians remain in fact Hermitian, this seeming non-Hermiticity should not be eliminated by any nonunitary transformation.
Covariant classical particle dynamics is described, and the associated covariant relativistic particle quantum mechanics is derived. The invariant symmetric bracket is defined on the space of quantum amplitudes, and its relation to a generalized Hamiltonian dynamics and to a covariant Schrödinger type equation is shown. Examples for relativistic potential problems are solved. Mathematically and physically acceptable probability densities for the Klein-Gordon equation and for the Dirac equation are derived, and a new continuity equation for each case is given. The quantum distribution for mass is discussed, and unambiguous representations of four-velocity and four-acceleration operators are given.
In this work we take a closer look at the algebraic-operator correspondence between the momentum space and the position space which defines the form of the canonical momentum operator in position space in Quantum Mechanics (QM). Starting from the Fourier transform (FT) relationship, we present a Hermitian generalization of the canonical momentum operator in position space. The action of the generalized operator is found to generate a local flow accompanied by position-dependent rescaling, rather than a global translation. Explicit eigenfunctions are obtained for representative cases and are shown to possess a well-defined limit to the plane-wave solution in QM. As an illustration, the infinite square well problem is solved using the generalized operator, yielding a deformed spectrum that has a smooth limit to the standard QM result.
In this paper, we further study the G-dynamics newly emerged in the covariant dynamics defined by the QCPB theory. Then we want to seek the precise formulations of the G-dynamics to calculate the practical quantum problems. We explicitly verify how the role of G-dynamics plays in quantum mechanics, and then we propose three new operators based on the G-dynamics: D-operator, T-operator and G-operator, we find that the non-Hermitian operators are inevitable to appear in the framework of the QCPB. Then the eigenvalue equation of them are discussed accordingly by using the Schrodinger equation and geometrinetic energy operator (GEO) which leads to the Ri-operator, respectively, we obtain some useful results between two quantum situations. Meanwhile, we present generalized covariant wave equation based on the G-operator. The GEO for quantum harmonic oscillator as an application is further calculated.
Based on (i) the spectral resolution definition of the momentum operator, (ii) the linearity of correspondence between physical observables and quantum Hermitian operators, (iii) the definition of conjugate coordinate-momentum variables in classical mechanics, and (iv) the invariance of the classical Hamiltonian to canonical transformations (transformations that change from one set of conjugate variables to another), we show that the $[\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{x},\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{p}]$ coordinate-momentum commutator must have the value ihihih where hhh is a real nonzero number (which we can identify with the experimentally determined $\ensuremath{\hbar}$). The results are then extended to include all generalized coordinates and their conjugate momenta as well as the Cartesian special-relativistic case.