Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgements
- Introduction
- Part I General Properties of Fields; Scalars and Gauge Fields
- 1 Short Review of Classical Mechanics
- 2 Symmetries, Groups, and Lie algebras; Representations
- 3 Examples: The Rotation Group and SU(2)
- 4 Review of Special Relativity: Lorentz Tensors
- 5 Lagrangeans and the Notion of Field; Electromagnetism as a Field Theory
- 6 Scalar Field Theory, Origins, and Applications
- 7 Nonrelativistic Examples:WaterWaves and Surface Growth
- 8 Classical Integrability: Continuum Limit of Discrete, Lattice, and Spin Systems
- 9 Poisson Brackets for Field Theory and Equations of Motion: Applications
- 10 Classical Perturbation Theory and Formal Solutions to the Equations of Motion
- 11 Representations of the Lorentz Group
- 12 Statistics, Symmetry, and the Spin-Statistics Theorem
- 13 Electromagnetism and the Maxwell Equation; Abelian Vector Fields; Proca Field
- 14 The Energy-Momentum Tensor
- 15 Motion of Charged Particles and ElectromagneticWaves; Maxwell Duality
- 16 The Hopfion Solution and the Hopf Map
- 17 Complex Scalar Field and Electric Current: Gauging a Global Symmetry
- 18 The Noether Theoremand Applications
- 19 Nonrelativistic and Relativistic Fluid Dynamics: Fluid Vortices and Knots
- Part II Solitons and Topology; Non-Abelian Theory
- Part III Other Spins or Statistics; General Relativity
- References
- Index
17 - Complex Scalar Field and Electric Current: Gauging a Global Symmetry
from Part I - General Properties of Fields; Scalars and Gauge Fields
Published online by Cambridge University Press: 04 March 2019
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgements
- Introduction
- Part I General Properties of Fields; Scalars and Gauge Fields
- 1 Short Review of Classical Mechanics
- 2 Symmetries, Groups, and Lie algebras; Representations
- 3 Examples: The Rotation Group and SU(2)
- 4 Review of Special Relativity: Lorentz Tensors
- 5 Lagrangeans and the Notion of Field; Electromagnetism as a Field Theory
- 6 Scalar Field Theory, Origins, and Applications
- 7 Nonrelativistic Examples:WaterWaves and Surface Growth
- 8 Classical Integrability: Continuum Limit of Discrete, Lattice, and Spin Systems
- 9 Poisson Brackets for Field Theory and Equations of Motion: Applications
- 10 Classical Perturbation Theory and Formal Solutions to the Equations of Motion
- 11 Representations of the Lorentz Group
- 12 Statistics, Symmetry, and the Spin-Statistics Theorem
- 13 Electromagnetism and the Maxwell Equation; Abelian Vector Fields; Proca Field
- 14 The Energy-Momentum Tensor
- 15 Motion of Charged Particles and ElectromagneticWaves; Maxwell Duality
- 16 The Hopfion Solution and the Hopf Map
- 17 Complex Scalar Field and Electric Current: Gauging a Global Symmetry
- 18 The Noether Theoremand Applications
- 19 Nonrelativistic and Relativistic Fluid Dynamics: Fluid Vortices and Knots
- Part II Solitons and Topology; Non-Abelian Theory
- Part III Other Spins or Statistics; General Relativity
- References
- Index
Summary
We study complex scalar fields and their couplings. A complex scalar with a global U(1) invariance has an electric current and associated charge, and we can “gauge” this symmetry, i.e., make it local. The procedure for making it local is the Noether procedure, and it amounts to making derivatives covariant with respect to a gauge field (minimal coupling to the gauge field), plus adding more terms.
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- Classical Field Theory , pp. 158 - 164Publisher: Cambridge University PressPrint publication year: 2019