instanton
Sign in to saveAn instanton (or pseudoparticle) is a notion appearing in theoretical and mathematical physics. An instanton is a classical solution to equations of motion with a finite, non-zero action, either in quantum mechanics or in quantum field theory. More precisely, it is a solution to the equations of motion of the classical field theory on a Euclidean spacetime.
Article
18 sectionsContents
- Mathematics
- Quantum mechanics
- Motivation of considering instantons
- WKB approximation
- Path integral interpretation via instantons
- Explicit formula for double-well potential
- Results
- Periodic instantons
- Instantons in reaction rate theory
- Inverted double-well formula
- Quantum field theory
- Yang–Mills theory
- Various numbers of dimensions
- 4d supersymmetric gauge theories
- Explicit solutions on R<sup>4</sup>
- See also
- References and notes
- External links
An instanton (or pseudoparticle) is a notion appearing in theoretical and mathematical physics. An instanton is a classical solution to equations of motion with a finite, non-zero action, either in quantum mechanics or in quantum field theory. More precisely, it is a solution to the equations of motion of the classical field theory on a Euclidean spacetime.
In such quantum theories, solutions to the equations of motion may be thought of as critical points of the action. The critical points of the action may be local maxima of the action, local minima, or saddle points. Instantons are important in quantum field theory because: they appear in the path integral as the leading quantum corrections to the classical behavior of a system, and they can be used to study the tunneling behavior in various systems such as a Yang–Mills theory.