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Hadron contribution to effective degrees of freedom in early Universe
In transition from quark-gluon plasma to hadron gas in the early Universe, the value of the effective degrees of freedom $g_{\star}$ decreases abruptly. This seems to me like a sort of decoupling: ...
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graph relativistic degrees of freedom
I'm trying to graph the relativistic degrees of freedom, which should look like the figure
And I am trying to guide me with this Phys.SE answer: Number $g(T)$ of relativistic degrees of freedom as a ...
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3
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Degrees of freedom in the early Universe
I am reading Dodelson's textbook on cosmology. On page 66 we find equation 3.26:
$$\rho = \frac{\pi^2}{30}T^4\biggl[\sum_{i=\text{bosons}}g_i+\frac{7}{8}\sum_{i=\text{fermions}}g_i\biggr]\equiv g_\...
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Do photons have six degrees of freedom?
Calculations involving pressure and volume relationships of photon gas during the cosmologic expansion of the universe posit an adiabatic cooling process with a heat capacity ration of 4/3.
This ratio ...
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