Consider a flat expanding universe with no cosmological constant and no curvature (k=0 in the Einstein...

Consider a flat expanding universe with no cosmological constant and no curvature (k=0 in the Einstein equations). Show that if the Universe is made of "dust", so the energy density scales like 1/a^3, then the scale factor, a(t), grows as t^(2/3). Show if it is made of radiation (so the energy density scales as 1/a^4 -- the extra factor of a comes from the redshift), then it grows as t^(1/2). In both cases, show that for early times, the scale factor grows faster than light. Is this a problem?

Expert Solution

genius_generous answered 1 year ago

The Hubble Constant, the density of the universe, and the cosmological constant are all vital to...

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Consider the equilibrium N2(g) + O2(g) ⇄ 2 NO(g) At 2300 K the equilibrium constant K...

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Consider steady heat transfer between two large parallel plates at constant temperatures of T1 582 K...

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