User Wild Feather

4 votes

3 answers

673 views

Is the parity operator an observable?

asked Jun 12, 2020 at 8:23

4 votes

3 answers

107 views

Why do free-falling particles converge onto the Hubble flow?

asked Jan 8 at 13:39

2 votes

1 answer

107 views

Why is cosmological time unique?

asked Jan 12 at 10:12

2 votes

1 answer

86 views

Concept of distance in cosmology

asked Jan 13 at 14:23

2 votes

1 answer

156 views

Poisson equation in universe with gravity and expansion

asked Jul 24 at 18:42

2 votes

2 answers

3k views

Expected value of linear momentum with real wave function

asked Feb 1, 2021 at 9:40

1 vote

1 answer

91 views

Dimensionless power spectrum

asked Oct 6, 2022 at 19:10

1 vote

2 answers

2k views

Variation of resistance with temperature in semiconductors

asked Oct 18, 2017 at 16:46

1 vote

1 answer

69 views

Different definitions of recession velocity

asked Jan 19 at 9:50

1 vote

2 answers

150 views

Continuity equation for the conservation of energy from the conservation of the energy-momentum tensor

asked Jan 27 at 10:24

1 vote

2 answers

159 views

Upper index covariant derivative $\nabla^\mu$

asked Feb 2 at 18:39

1 vote

1 answer

320 views

Compute density of states in momentum space and in phase space

asked Feb 11 at 19:54

1 vote

0 answers

52 views

Contraction of distances in explanation of relativity of simultaneity in special relativity

asked Mar 9 at 10:09

1 vote

1 answer

60 views

How to express symmetry of a mixed (1,1) tensor with upper and lower index?

asked Mar 15 at 10:24

1 vote

1 answer

38 views

Poisson equation in Cosmology at first order in perturbation theory

asked Jul 26 at 8:25

1 vote

0 answers

41 views

Momentum in terms of comoving velocity in cosmology

asked Aug 27 at 19:41

1 vote

1 answer

44 views

Sign convention for the Lagrangian of a free massive point particle in general relativity

asked Sep 15 at 17:14

1 vote

0 answers

45 views

Spatial and temporal derivatives of a perturbation

asked Apr 18 at 10:13

1 vote

0 answers

52 views

Gravitational potential for concentric spherical shells

asked May 17 at 18:13

1 vote

0 answers

58 views

Dirac delta in Fourier space for finite volume

asked Jun 13 at 10:02

1 vote

1 answer

61 views

Fourier transform of the top-hat filter [closed]

asked Jul 12 at 13:45

0 votes

1 answer

82 views

Calculation about two-point correlation function in Fourier space

asked May 8 at 18:11

0 votes

1 answer

62 views

Calculating distance from the FRW metric

asked Jan 17 at 18:54

0 votes

0 answers

24 views

How does the gravitational potential change when using physical instead of comoving coordinates?

asked Jul 26 at 8:58

0 votes

1 answer

89 views

How to prove Poisson equation for the peculiar potential in Cosmology

asked Aug 13 at 19:51

0 votes

1 answer

34 views

Elementary calculation of the critical density

asked Apr 4 at 14:52

0 votes

1 answer

49 views

Integration constant in $a(t)$ for the Einstein-de Sitter universe

asked Apr 9 at 18:48

0 votes

1 answer

84 views

Explanation for the value of the Hubble radius

asked Apr 10 at 9:15

0 votes

2 answers

63 views

Prove expression for center of mass of a curve [closed]

asked Feb 5, 2018 at 16:57

0 votes

1 answer

66 views

Variational method when the Hamiltonian commutes with the parity operator

asked Jul 6, 2020 at 9:54

Stack Exchange Network

33 Questions

Is the parity operator an observable?

Why do free-falling particles converge onto the Hubble flow?

Why is cosmological time unique?

Concept of distance in cosmology

Poisson equation in universe with gravity and expansion

Expected value of linear momentum with real wave function

Dimensionless power spectrum

Variation of resistance with temperature in semiconductors

Different definitions of recession velocity

Continuity equation for the conservation of energy from the conservation of the energy-momentum tensor

Upper index covariant derivative $\nabla^\mu$

Compute density of states in momentum space and in phase space

Contraction of distances in explanation of relativity of simultaneity in special relativity

How to express symmetry of a mixed (1,1) tensor with upper and lower index?

Poisson equation in Cosmology at first order in perturbation theory

Momentum in terms of comoving velocity in cosmology

Sign convention for the Lagrangian of a free massive point particle in general relativity

Spatial and temporal derivatives of a perturbation

Gravitational potential for concentric spherical shells

Dirac delta in Fourier space for finite volume

Fourier transform of the top-hat filter [closed]

Calculation about two-point correlation function in Fourier space

Calculating distance from the FRW metric

How does the gravitational potential change when using physical instead of comoving coordinates?

How to prove Poisson equation for the peculiar potential in Cosmology

Elementary calculation of the critical density

Integration constant in $a(t)$ for the Einstein-de Sitter universe

Explanation for the value of the Hubble radius

Prove expression for center of mass of a curve [closed]

Variational method when the Hamiltonian commutes with the parity operator