"Negative one times pressure times the derivative of the cube of this quantity" equals the derivative of the product of energy density and the cube of this quantity, according to one form of the first law of thermodynamics.
"Negative one times pressure times the derivative of the cube of this quantity" equals the derivative of the product of energy density and the cube of this quantity, according to one form of the first law of thermodynamics. In the lambda-CDM model, density parameter components appear as coefficients of powers of this quantity on one side of the Friedmann equation. The square of this quantity equals "six times intrinsic curvature divided by the spatial Ricci scalar" and acts as a multiplicative prefactor in the definition of the Robertson-Walker metric. Subtracting one from this quantity's inverse gives the cosmological redshift, and dividing this quantity's derivative by this quantity gives the Hubble parameter. Its value ranges from zero at the Big Bang to one at the present age of the universe. For 10 points, name this dimensionless quantity, defined as the ratio of the proper distance between two objects at some time to that distance at a reference time, which measures the universe's rate of expansion.
"Negative one times pressure times the derivative of the cube of this quantity" equals the derivative of the product of energy density and the cube of this quantity, according to one form of the first law of thermodynamics.
scale factor [prompt on "a of t"]