3 votes

How does dark energy affect the dynamics of galaxy clusters?

Systems of orbiting material exceed the cosmological average density by a factor of around 200 (the "virial overdensity"). So dark energy makes only a percent-level contribution to the ...
Sten's user avatar
  • 2,658
2 votes
Accepted

Why isn't the curvature scale in Robertson-Walker metric dynamic?

Your generalized metric fails to be homogeneous. It's isotropic, but only around the privileged center of the universe ($r=0$). One way of showing that is to compute the Ricci scalar curvature; you'll ...
benrg's user avatar
  • 24.2k
2 votes

Is there a GR explanation for cosmological coupling causing mass increase as the universe expands?

Perhaps this is a late answer, but in addition to TimRias answer: Our universe is not just de-Sitter but FLRW. The latter is more general in the sense that the scale factor $a(t)$ can take arbitrary ...
S.G's user avatar
  • 947
1 vote

Why easiest path from Big Bang to Heat Death is not followed by nature?

Sounds like you're asking why the universe started out in a highly ordered state, and not in a highly disordered state (which would be immediate heat death). The answer is we don't know, because we ...
Allure's user avatar
  • 19.4k
1 vote

What is the correlation between the Hubble tension and Dark Energy?

The calculation of the present-day value of the Hubble parameter $H_0$ can be done either by looking at the local value of the Hubble parameter, which is done they the observation of type Ia ...
S.G's user avatar
  • 947
1 vote

What is the correlation between the Hubble tension and Dark Energy?

Dark energy (and no doubt the OP read something like the NASA page) has a lot to do with the Hubble Tension. The so-called local/late Universe measurement (i.e. SH$0$ES $H_0=73.04\pm{1.04}$) derived ...
Mr Anderson's user avatar
  • 1,343
1 vote
Accepted

What does it mean for a black hole to be "filled" with vacuum energy?

They proposes that all small-scale inhomogeneity should contribute to the pressure term in the Friedmann equations, including the pressure within the cores of compact objects. Let us write the perfect ...
S.G's user avatar
  • 947

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