Dirac equation Definition and 166 Threads

  1. D

    What is the Dirac Equation and How Did it Predict the Existence of Anti-Matter?

    Hi I'm curious, how did the dirac equation predict the existence of anti matter? what was the mechanism that made physicists believe it existed? Thank you
  2. K

    Negative energy in Dirac equation

    When Dirac solved his equation for electron, he found out there are negative energy states. My question is why electrons won't jump from positive energy state to negative energy states and release energy as photon? Dirac proposed that all negative energy states have been filled so electrons...
  3. T

    Deriving the continuity equation from the Dirac equation (Relativistic Quantum)

    So I am trying to derive the continuity equation: \frac{\partial}{\partial x^{\mu}}J^{\mu} = 0 From the Dirac equation: i\gamma^{\mu} \frac{\partial}{\partial x^{\mu}}\Psi - \mu\Psi = 0 And its Hermitian adjoint: i\frac{\partial}{\partial x^{\mu}}\overline{\Psi}\gamma^{\mu} -...
  4. J

    Dirac equation and general covariance

    According to the principle of general covariance, the form of equations should be independent of the coordinates chosen. In general relativity, this is implemented by expressing laws of physics as tensor equations. In physics equations are often expressed in index notation, which allows...
  5. T

    Obtaining Dirac equation from symmetries

    If we consider nonrelativistic QM, we will find Galilean group under the hood. Thanks to this, group theory enables us to find equations of motion directly from the symmetry principles. For example, if we take only geometric symmetries, we will get that the state space is broken into irreducible...
  6. A

    Time evolution and the Dirac Equation

    I have a question about the Dirac Equation. I know that if I have a given initial state in non-relativistic quantum mechanics, I can find the Fourier coefficients using that state, and then write down the wavefunction for any time. But if I have an initial state wavefunction (that is, the...
  7. M

    Dirac Equation and Spinor Field Transformations: Understanding the Basics

    Dirac equation and friends :) I was playing with Dirac equations and deriving some usefull details, Note sure for a calculation, is all the math right? Beginning: we require for a pure Lorentz trasf that the spinor field trasform linearly as: \psi'(x')=S(\Lambda)\psi(x)...
  8. R

    Understanding the Dirac Equation: Showing \gamma^{\mu} Must Be Square Matrices

    Yep, another quick question on the Dirac Equation! I've become slightly more clued about the use of the DE now in illustrating the negative energy problem in relativistic QM as well as the existence of spin, however one thing is still puzzling me. I've read this excerpt in a text: I'm...
  9. R

    Solve the Dirac Equation: Unraveling Anticommutator Mystery

    [SOLVED] The Dirac Equation I'm trying to understand the following property of the Dirac equation: (i \gamma^{\mu}\partial_{\mu} - m)\Psi(x) = 0 Acting twice with (i \gamma^{\mu}\partial_{\mu} - m): (i \gamma^{\mu}\partial_{\mu} - m)^{2} \Psi(x) = 0 = [ -...
  10. M

    The Dirac Equation and the Neutrinos

    Does the Dirac equation predicts the fact that there are no right handed neutrinos?
  11. I

    How Does Chirality Impact the Dirac and Weyl Equations?

    What results in Chirality? And what is the physical implication of chirality in Dirac equation?
  12. J

    What's the best book/website on the Dirac equation?

    Did Feynman write about the Dirac Equation? I would like to see how to derive it, and how it reduces to the Schrodenger equation.
  13. R

    On the Dirac equation in a gravitation field

    Let's discuss the Dirac equation in a gravitation field. I suggest to begin with the following article: http://arxiv.org/abs/math.DG/0603367" It is rather simple. Your comments would be helpful for me.
  14. C

    Dirac equation from random walk

    I was unaware that one could obtain the Dirac equation as a result of a random walk. I believe that this has been done by other researchers, but I found it by Ord's papers: http://arxiv.org/find/quant-ph/1/au:+Ord_G/0/1/0/all/0/1 Anyone else find these interesting? My interest is due to...
  15. S

    Dirac equation and path integral

    Hello How to get the propagator for the Dirac equation (1+1) and forth and what about the Feynman's Checkerboard (or Chessboard) model Thanks I need Your help
  16. arivero

    Van der Waerden's Derivation of the Dirac Equation

    Sakurai credits B. L. van der Waerden 1932 a pretty derivation of Dirac equation from two-component wave functions. First decompose E^2-p^2=m^2 as (i \hbar {\partial \over \partial x_0} + {\bf \sigma} . i \hbar \nabla) (i \hbar {\partial \over \partial x_0} - {\bf \sigma} . i \hbar...
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