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6

We want the Newtonian limit of the Einstein Field equations for nonzero vacuum energy(=cosmological constant). As $\rho_\mathrm{vac}=\Lambda/4\pi G$ is a mass(=energy) density, Poisson equation is $$ \Delta\Phi=4\pi G\rho(\boldsymbol r)-\Lambda \tag{1} $$ If we assume spherical symmetry, and point-like source $\rho\sim\delta(\boldsymbol r)$, the ...


3

You get an extra term that increases with r: $$a = -\frac{G\cdot M}{r^2} + j\cdot r$$ with j as the repulsive component.


8

The Big Bang Theory is a much more general and less specific description of our theory about the origin of the Universe than the $\Lambda{\rm CDM}$ model (by the way, I don't think that the hyphen is written in that acronym). The Big Bang Theory says that the Universe was expanding and the distances between two places where galaxies sit today used to be ...


1

Good question. Not clear to me it reaches infinity, or high enough for a singularity. It seems that if one is talking about non accelerating, i.e. Inertial, observers in a de Sitter spacetime, it is a constant temperature determined by the cosmological constant. The cosmological constant is constant in de Sitter, and per current observations. Please note ...


4

The cosmological redshift of a galaxy is not interpreted as being due to the velocity of that galaxy away from us (the special relativistic interpretation), but rather as being being due the effect of the expanding space on the traveling photon (the general-relativistic interpretation).$^\dagger$ This expansion in turn makes the galaxies recede from us at a ...


0

You say right as Hubble's law state that farthest the galaxy is faster it is receding from us. $v=Hl$. H is Hubble constant. $H(t)=\frac{\dot{a(t)}}{a(t)}$, a(t) is scale factor. Experimentally it is confirmed by observing the radiation from distant object. Due to Doppler's effect observed frequency of light will be different from emitted one and it depends ...


0

what is dark matter ??? We know how much dark energy there is because we know how it affects the Universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the Universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ...


0

what is dark matter ??? We know how much dark energy there is because we know how it affects the Universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the Universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, ...



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