Dirac equation continuity issue

In summary, the conversation discusses the continuity of the Dirac equation and the concern that the momentum operator should be Hermitian, but there is a change of sign in the equation. The speaker wonders if there should be a change in the gradient to preserve the Hermitian nature of the momentum operator. They express a willingness to try and prove this themselves, but are unsure of where to start.
  • #1
raymo39
50
0
So I definitely believe that the continuity of the Dirac equation holds, there is one thing that annoys me, which is that

[tex] c \alpha . (-i \hbar \nabla \psi ) = c (i \hbar \nabla \psi^\dagger ) . \alpha [/tex]

from the first part of the Dirac Hamiltonian
because the momentum operator should be Hermitian, but there is clearly a change of sign. I realize that the Hermitian conjugate of the spinor is now differently oriented, but shouldn't there be a change in ∇ such that its hermitian adjoint is negative itself to preserve the Hermitian nature of p?
I'm quite happy to try and prove this myself, but I am a bit lost as to where to start
 
Last edited:
Physics news on Phys.org
  • #2
momentum operator is defined as in schrodinger one,i.e. p=-ih-∇,which is hermitian as everyone knows.
 

Related to Dirac equation continuity issue

1. What is the Dirac equation continuity issue?

The Dirac equation continuity issue is a problem in theoretical physics that arises from the Dirac equation, which describes the behavior of elementary particles such as electrons. The issue concerns the apparent discontinuity between the solutions of the Dirac equation for positive and negative energies.

2. How does the Dirac equation relate to the concept of antimatter?

The Dirac equation was first developed by British physicist Paul Dirac in the 1920s to describe the behavior of electrons, but it also predicts the existence of antimatter. Antimatter is a form of matter composed of antiparticles, which have the same mass as their corresponding particles but opposite charges. The Dirac equation explains that antimatter particles have negative energy solutions, while normal matter particles have positive energy solutions.

3. What is the significance of the Dirac equation continuity issue?

The Dirac equation continuity issue has important implications for our understanding of the fundamental laws of physics. It has been a major challenge in theoretical physics for decades and has led to the development of new theories and concepts, such as the concept of vacuum fluctuations and the concept of negative energy states.

4. How have scientists attempted to resolve the Dirac equation continuity issue?

Several theories have been proposed to resolve the Dirac equation continuity issue, including the Klein paradox, which suggests that negative energy solutions correspond to the creation of particle-antiparticle pairs. Another theory is the concept of Zitterbewegung, which describes the rapid oscillations of a particle's position predicted by the Dirac equation. Other proposals include the concept of vacuum fluctuations and the idea of a hidden variable that maintains the continuity of the Dirac equation.

5. Has the Dirac equation continuity issue been resolved?

The Dirac equation continuity issue remains an open problem in theoretical physics, and there is currently no consensus on a definitive solution. However, various theories and proposals have shed light on the issue and have advanced our understanding of the fundamental laws of physics. Ongoing research and advancements in technology may eventually lead to a resolution of this long-standing issue.

Similar threads

Replies
9
Views
518
  • Quantum Physics
Replies
2
Views
914
  • Differential Geometry
Replies
1
Views
1K
  • Quantum Physics
Replies
8
Views
2K
  • Quantum Physics
Replies
6
Views
2K
Replies
6
Views
1K
Replies
12
Views
2K
Replies
4
Views
1K
Replies
1
Views
655
  • Quantum Physics
Replies
9
Views
905
Back
Top