User Nicholas Engelbert

5 votes

1 answer

808 views

Why is the Lorentz boost a non-unitary operator in the single electron theory?

asked Apr 29, 2021 at 20:37

4 votes

1 answer

663 views

Dirac spinor's non-unitary representation of the Poincaré group leads me to conclude that Dirac spinors are not "quantum states" in the usual sense

asked Jun 20, 2021 at 23:00

4 votes

2 answers

316 views

Hilbert space and wave functions of single-particle states in QFT (Weinberg)

asked Aug 2, 2021 at 20:10

4 votes

1 answer

374 views

Why does spin, and not total angular momentum, couple to the magnetic field in a Stern-Gerlach experiment?

asked Feb 12, 2021 at 18:45

2 votes

1 answer

109 views

Does every Hilbert space contain the generators of the Poincaré algebra?

asked Feb 12, 2021 at 19:25

2 votes

1 answer

310 views

Stern-Gerlach with particles that are not electrically neutral. Can I "ignore" the Lorentz force?

asked Mar 23, 2021 at 17:18

2 votes

1 answer

204 views

Effects of a Lorentz boost on the normalization of a probability density (Dirac equation)

asked Jun 14, 2021 at 23:28

1 vote

0 answers

21 views

Velocity vector (of an inertial frame) from the Lorentz transformation matrix [duplicate]

asked Aug 2, 2021 at 18:54

1 vote

0 answers

115 views

Weinberg's normalization convention for momentum eigenstates

asked Aug 25, 2021 at 22:56

1 vote

0 answers

77 views

Help with the interpretation of electron-positron pairs in Feynman diagrams for Thomson scattering, in terms of the Dirac "hole theory"

asked Apr 8, 2021 at 20:23

1 vote

0 answers

51 views

In the Dirac single-particle theory, what's the physical difference between these two spinors?

asked Apr 19, 2021 at 17:53

1 vote

1 answer

367 views

Hamiltonian operator vs zeroth component of the momentum four-vector

asked Jan 27, 2021 at 22:31

0 votes

1 answer

415 views

Obtaining the Pauli spinor from the Dirac spinor

asked Jan 21, 2021 at 15:25

0 votes

0 answers

87 views

Vector potential for an inhomogeneous magnetic field

asked Feb 18, 2021 at 23:04

0 votes

1 answer

923 views

Pauli matrices in the Heisenberg picture

asked Mar 23, 2021 at 0:42

0 votes

0 answers

166 views

Obtaining the unitary representation of the Lorentz group from infinitesimal transformations

asked Dec 7, 2021 at 3:54

Stack Exchange Network

16 Questions

Why is the Lorentz boost a non-unitary operator in the single electron theory?

Dirac spinor's non-unitary representation of the Poincaré group leads me to conclude that Dirac spinors are not "quantum states" in the usual sense

Hilbert space and wave functions of single-particle states in QFT (Weinberg)

Why does spin, and not total angular momentum, couple to the magnetic field in a Stern-Gerlach experiment?

Does every Hilbert space contain the generators of the Poincaré algebra?

Stern-Gerlach with particles that are not electrically neutral. Can I "ignore" the Lorentz force?

Effects of a Lorentz boost on the normalization of a probability density (Dirac equation)

Velocity vector (of an inertial frame) from the Lorentz transformation matrix [duplicate]

Weinberg's normalization convention for momentum eigenstates

Help with the interpretation of electron-positron pairs in Feynman diagrams for Thomson scattering, in terms of the Dirac "hole theory"

In the Dirac single-particle theory, what's the physical difference between these two spinors?

Hamiltonian operator vs zeroth component of the momentum four-vector

Obtaining the Pauli spinor from the Dirac spinor

Vector potential for an inhomogeneous magnetic field

Pauli matrices in the Heisenberg picture

Obtaining the unitary representation of the Lorentz group from infinitesimal transformations