User AlfredV

13 votes

3 answers

7k views

Why symmetry transformations have to commute with Hamiltonian?

asked May 3, 2019 at 22:12

5 votes

3 answers

346 views

Definition of Newton's first law [duplicate]

asked May 12, 2019 at 0:49

5 votes

0 answers

88 views

Why is Gell-Mann and Low theorem valid only for non-degenerate non-perturbed states?

asked Jul 9, 2020 at 17:18

4 votes

0 answers

142 views

The validity of the Gell-Mann and Low theorem for non-normalizable state $\phi_{0}$?

asked Apr 11, 2020 at 3:36

3 votes

2 answers

737 views

A book on special special relativity covering covariant and contravariant tensors [duplicate]

asked May 10, 2019 at 14:28

2 votes

1 answer

2k views

Lehmann representation of Green function

asked Nov 1, 2019 at 0:31

2 votes

3 answers

88 views

Does the set of the degenerated eigenfunctions of hamiltonian forms a subspace?

asked May 5, 2019 at 0:53

2 votes

2 answers

1k views

How to determine if a tensor is covariant or contravariant?

asked May 24, 2019 at 14:11

1 vote

1 answer

554 views

Representation and Lie algebra of $SO(3)$

asked Jun 1, 2019 at 13:31

1 vote

1 answer

257 views

Interpretation of field operators

asked Jun 11, 2019 at 13:19

1 vote

1 answer

82 views

The differentiation of a functional by a ket

asked May 5, 2019 at 20:54

1 vote

1 answer

69 views

Integral convergence in scattering problem

asked May 6, 2019 at 12:46

1 vote

1 answer

494 views

The form of electronic density in DFT

asked Jan 27, 2020 at 23:01

1 vote

1 answer

168 views

Resolving Power of Optical Instruments and coherent light

asked Sep 19, 2023 at 13:31

1 vote

1 answer

145 views

Representations of the rotation group

asked May 24, 2019 at 0:49

1 vote

0 answers

102 views

Independents fields and the Lagrange Density of Schrodinger equation [duplicate]

asked Jun 21, 2019 at 21:16

1 vote

1 answer

542 views

Exact differentials in thermodynamics

asked Jul 4, 2019 at 23:41

1 vote

1 answer

481 views

Interpretation of creation and annihilation operators acting in the state of a interacting system

asked Jul 13, 2019 at 13:09

1 vote

0 answers

321 views

Generalization of Wick's Theorem [duplicate]

asked Sep 6, 2019 at 15:08

1 vote

0 answers

160 views

The Gell-Mann and Low theorem and the expansion of the Green function

asked Oct 11, 2019 at 22:21

0 votes

2 answers

647 views

Commutation of field operators with differents times

asked Oct 22, 2019 at 18:44

0 votes

1 answer

202 views

Completeness relations in propagators

asked Jul 22, 2019 at 13:30

0 votes

0 answers

240 views

Normal-Ordering of operators of two different types of fermions

asked Aug 2, 2019 at 21:18

0 votes

1 answer

349 views

Contribution of a second-order Feynman diagram for the one-particle Green function

asked Jul 12, 2019 at 22:57

0 votes

2 answers

167 views

Variation of entropy in a transference of heat

asked Aug 4, 2020 at 15:02

0 votes

1 answer

169 views

The spin degeneracy and the adiabatic theorem

asked Aug 26, 2020 at 23:03

0 votes

2 answers

970 views

Normalization in perturbation theory

asked Mar 21, 2020 at 0:23

0 votes

1 answer

37 views

Symmetry of an interacting and a non-interacting state of a quantum system

asked Apr 25, 2020 at 15:20

0 votes

3 answers

2k views

A book for relativistic quantum mechanics

asked May 15, 2019 at 1:00

0 votes

1 answer

499 views

$\mathrm{SU}(2)$ as a representation of the rotation group

asked May 19, 2019 at 19:49

Stack Exchange Network

36 Questions

Why symmetry transformations have to commute with Hamiltonian?

Definition of Newton's first law [duplicate]

Why is Gell-Mann and Low theorem valid only for non-degenerate non-perturbed states?

The validity of the Gell-Mann and Low theorem for non-normalizable state $\phi_{0}$?

A book on special special relativity covering covariant and contravariant tensors [duplicate]

Lehmann representation of Green function

Does the set of the degenerated eigenfunctions of hamiltonian forms a subspace?

How to determine if a tensor is covariant or contravariant?

Representation and Lie algebra of $SO(3)$

Interpretation of field operators

The differentiation of a functional by a ket

Integral convergence in scattering problem

The form of electronic density in DFT

Resolving Power of Optical Instruments and coherent light

Representations of the rotation group

Independents fields and the Lagrange Density of Schrodinger equation [duplicate]

Exact differentials in thermodynamics

Interpretation of creation and annihilation operators acting in the state of a interacting system

Generalization of Wick's Theorem [duplicate]

The Gell-Mann and Low theorem and the expansion of the Green function

Commutation of field operators with differents times

Completeness relations in propagators

Normal-Ordering of operators of two different types of fermions

Contribution of a second-order Feynman diagram for the one-particle Green function

Variation of entropy in a transference of heat

The spin degeneracy and the adiabatic theorem

Normalization in perturbation theory

Symmetry of an interacting and a non-interacting state of a quantum system

A book for relativistic quantum mechanics

$\mathrm{SU}(2)$ as a representation of the rotation group