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bhapi
  • Member for 6 years, 5 months
  • Last seen more than 4 years ago
3 votes
1 answer
2k views

Number density of photons and the total energy of the universe

1 vote
1 answer
4k views

number density of photons

1 vote
2 answers
2k views

A simple question on finding the number of macro states for a system of two Einstein solids

0 votes
1 answer
1k views

Calculating the Earth-Sun distance

0 votes
1 answer
30 views

should I treat $P_c$ as a constant of integration when finding P(r0 the pressure in a gas cloud?

0 votes
1 answer
29 views

What condition needs to be met before a type of matter dominates the density of the universe

0 votes
1 answer
260 views

How is the co-moving co-ordinate defined mathematically in cosmology?

0 votes
2 answers
319 views

Does the Lorentz transformation as $c \rightarrow ∞$ reproduce the Galilean transformation?

0 votes
1 answer
148 views

General formula for relativistic Energy/momentum conservation?

0 votes
3 answers
3k views

Help trying to understand why the matrix representation of $J^2$ is what it is

0 votes
1 answer
52 views

Distinction between these closely related angular momentum concepts

0 votes
1 answer
67 views

A question on perturbative terms involved in the hyperfine structure of hydrogen

0 votes
1 answer
295 views

Why is $\Lambda=0$ for a flat matter dominated universe?

0 votes
1 answer
90 views

How is the energy density of radiation relatedd to the energy density of particles and the critical density?

-1 votes
1 answer
97 views

Is this the proper way to formulate kinetic energy of a 2 dimensional spring system? [closed]