| Expressions |
Definition |
| Dirac adjoint |
The Dirac adjoint \bar\psi of a Dirac spinor \ \psi is defined to be the dual spinor \ \psi^{\dagger} \gamma_0 , where \ \gamma_0 denotes the time-like Dirac matrix. (references) |
| Dirac comb |
Multiplication of a continuous signal by a Dirac comb is sometimes called an ideal sampler with sampling rate T. (references) |
| Dirac field |
In physics, a Dirac field is a fermionic field (usually a quantized field, as usual in quantum field theory) associated with spin 1/2 fermions such as the electron or muon. (references) |
| Dirac measure |
For any subset Z containing x. (references) |
| Dirac monopole |
In theoretical physics, the Dirac monopole is another name for the magnetic monopole; the article about the magnetic monopoles contains a lot of useful information. (references) |
| Dirac operator |
In mathematics and quantum mechanics, a Dirac operator is a differential operator that is a formal square root, or half-iterate, of a second-order operator such as a Laplacian. The original case which concerned Dirac was to factorise formally an operator for Minkowski space, to get a form of quantum theory compatible with special relativity; to get the relevant Laplacian as a product of first-order operators he introduced spinors. (references) |
| Dirac Prize |
Confusingly, there are two prominent awards in the field of theoretical physics and mathematics commonly known as the Dirac Prize, awarded by different organizations. (references) |
| Dirac sea |
The Dirac sea is a theoretical model of the vacuum as an infinite sea of particles possessing negative energy. It was invented by the British physicist Paul Dirac in 1930 to explain the anomalous negative-energy quantum states predicted by the Dirac equation for relativistic electrons. The positron, the antimatter counterpart of the electron, was originally conceived of as a hole in the Dirac sea, well before its experimental discovery in 1932. (references) |
| Dirac string |
In physics, a Dirac string is a fictitious one-dimensional curve in space, stretched from a magnetic monopole - also called the Dirac monopole - to infinity. The gauge potential cannot be defined on the Dirac string, but it is defined everywhere else. The Dirac string acts as the solenoid in the Aharonov-Bohm effect, and the requirement that the position of the Dirac string should not be observable implies the Dirac quantization rule: the product of a magnetic charge and an electric charge must always be an integer multiple of 2\pi. (references) |
| Gabriel Andrew Dirac |
Gabriel Andrew Dirac (1925-1984) was a mathematician. He was the stepson of Paul Dirac and nephew of Eugene Wigner. (references) |
| Paul Adrien Maurice Dirac |
English theoretical physicist who applied relativity theory to quantum mechanics and predicted the existence of antimatter and the positron (1902-1984). Source: Wordnet 3.0 Copyright © 2006 by Princeton University. All rights reserved. |
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Source: compiled by the editor from various references; see credits.
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