User Cuntista

2 votes

1 answer

1k views

Evaluating $\sigma^{\mu\nu}F_{\mu\nu}=i\alpha \cdot E+\Sigma\cdot B$ matrix, spin dependent term in quadratic Dirac equation

asked May 18, 2020 at 14:40

1 vote

1 answer

123 views

Relativistic invariants of a classical field in 4D fashion: why the relation between the components of the current density holds?

asked Sep 19, 2022 at 16:34

1 vote

2 answers

152 views

If the curl of the gradient is always zero why isn't it in vorticity definition? Kosterlitz - Thouless - Berezinsky topological transition

asked Nov 12, 2023 at 21:28

1 vote

1 answer

86 views

Wick rotation and Exponential mapping of an "imaginary" differential operator acting on a real-valued wavefunction

asked Nov 26, 2023 at 12:08

1 vote

0 answers

66 views

Relation beteen harmonic polynomials and spherical harmonics

asked Dec 4, 2023 at 15:23

1 vote

1 answer

223 views

Building 4-vectors out of Weyl spinors: Combining 2 independent Weyl spinors and a sigma matrix to get a 4-vector

asked Dec 18, 2023 at 23:37

1 vote

0 answers

46 views

Is really hermiticity necessary to be a physical observable? What about larger class of operators like PT invariant operators or pseudo hermitian one?

asked Sep 26, 2023 at 11:34

0 votes

0 answers

17 views

Tunneling lowers the energy of a ground state superposition of spins up and down in the quantum Ising model

asked Nov 5, 2023 at 22:23

0 votes

1 answer

306 views

Trick with "functional" derivative to evaluate commutators between diagonal hamiltonian and creation fermionic operator

asked Mar 13, 2020 at 18:18

0 votes

0 answers

217 views

Represent the Pauli 4-vector $\sigma^\mu$ as hermitian matrix of matrices due to the $SL(2,C)$ universal double cover of $SO^+(3,1)$

asked Dec 28, 2023 at 1:36

0 votes

1 answer

100 views

How to evaluate the action of a fractional differential momentum operator?

asked Sep 8, 2023 at 13:16

0 votes

1 answer

58 views

Special relativity - 2 astronauts syncronize their clocks and moves in different paths at different velocities, which clocks is left behind? and why? [closed]

asked Jan 1, 2021 at 13:58

-2 votes

1 answer

59 views

Product between Pauli 4-vectors ${\sigma^\mu}\bar{\sigma}^\nu-{\sigma}^\nu\bar{\sigma}^\mu$

asked Jul 25 at 15:14

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13 Questions

Evaluating $\sigma^{\mu\nu}F_{\mu\nu}=i\alpha \cdot E+\Sigma\cdot B$ matrix, spin dependent term in quadratic Dirac equation

Relativistic invariants of a classical field in 4D fashion: why the relation between the components of the current density holds?

If the curl of the gradient is always zero why isn't it in vorticity definition? Kosterlitz - Thouless - Berezinsky topological transition

Wick rotation and Exponential mapping of an "imaginary" differential operator acting on a real-valued wavefunction

Relation beteen harmonic polynomials and spherical harmonics

Building 4-vectors out of Weyl spinors: Combining 2 independent Weyl spinors and a sigma matrix to get a 4-vector

Is really hermiticity necessary to be a physical observable? What about larger class of operators like PT invariant operators or pseudo hermitian one?

Tunneling lowers the energy of a ground state superposition of spins up and down in the quantum Ising model

Trick with "functional" derivative to evaluate commutators between diagonal hamiltonian and creation fermionic operator

Represent the Pauli 4-vector $\sigma^\mu$ as hermitian matrix of matrices due to the $SL(2,C)$ universal double cover of $SO^+(3,1)$

How to evaluate the action of a fractional differential momentum operator?

Special relativity - 2 astronauts syncronize their clocks and moves in different paths at different velocities, which clocks is left behind? and why? [closed]

Product between Pauli 4-vectors ${\sigma^\mu}\bar{\sigma}^\nu-{\sigma}^\nu\bar{\sigma}^\mu$