Wild Feather's user avatar
Wild Feather's user avatar
Wild Feather's user avatar
Wild Feather
  • Member for 6 years, 7 months
  • Last seen more than a week ago
4 votes
3 answers
673 views

Is the parity operator an observable?

4 votes
3 answers
107 views

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

2 votes
1 answer
107 views

Why is cosmological time unique?

2 votes
1 answer
86 views

Concept of distance in cosmology

2 votes
1 answer
156 views

Poisson equation in universe with gravity and expansion

2 votes
2 answers
3k views

Expected value of linear momentum with real wave function

1 vote
1 answer
91 views

Dimensionless power spectrum

1 vote
2 answers
2k views

Variation of resistance with temperature in semiconductors

1 vote
1 answer
69 views

Different definitions of recession velocity

1 vote
2 answers
150 views

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

1 vote
2 answers
159 views

Upper index covariant derivative $\nabla^\mu$

1 vote
1 answer
320 views

Compute density of states in momentum space and in phase space

1 vote
0 answers
52 views

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

1 vote
1 answer
60 views

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

1 vote
1 answer
38 views

Poisson equation in Cosmology at first order in perturbation theory

1 vote
0 answers
41 views

Momentum in terms of comoving velocity in cosmology

1 vote
1 answer
44 views

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

1 vote
0 answers
45 views

Spatial and temporal derivatives of a perturbation

1 vote
0 answers
52 views

Gravitational potential for concentric spherical shells

1 vote
0 answers
58 views

Dirac delta in Fourier space for finite volume

1 vote
1 answer
61 views

Fourier transform of the top-hat filter [closed]

0 votes
1 answer
82 views

Calculation about two-point correlation function in Fourier space

0 votes
1 answer
62 views

Calculating distance from the FRW metric

0 votes
0 answers
24 views

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

0 votes
1 answer
89 views

How to prove Poisson equation for the peculiar potential in Cosmology

0 votes
1 answer
34 views

Elementary calculation of the critical density

0 votes
1 answer
49 views

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

0 votes
1 answer
84 views

Explanation for the value of the Hubble radius

0 votes
2 answers
63 views

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

0 votes
1 answer
66 views

Variational method when the Hamiltonian commutes with the parity operator