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Keywords relevant to
mass-energy
ingredients of the
observable universe:
- dark energy:
The dominant
mass-energy ingredient in the
modern/local
observable universe
in the Λ-CDM model.
Constant dark energy
(which is the assumption of the
Λ-CDM model) is equivalent
in its effect on the
expansion of the universe
and the
cosmic scale factor a(t)
to a
cosmological constant (AKA Lambda, Λ).
Hence, dark energy is often
given the symbol Λ.
According to Planck 2018,
Ω_Λ=0.6847.
- inflaton:
See
Wikipedia: inflaton.
- "matter"
(AKA ):
A shorthand
for non-relativistic matter:
i.e., matter
moving at
velocities <<
vacuum light speed c = 2.99792458*10**5 km/s ≅ 3*10**5 km/s = 1 ly/y
Li-39--40
The mass-energy
non-negligible contribution of
to the
observable universe
is only its
rest mass mass-energy.
consists of
Baryonic matter
(i.e.,
protons,
neutrons,
and electrons)
and dark matter
(meaning in this context
cold dark matter (CDM)).
The secondary
mass-energy ingredient in the
modern/local
observable universe
in the Λ-CDM model.
According to Planck 2018,
Ω_matter=0.3153.
- "radiation":
A shorthand for
extreme relativistic particles
important in cosmology.
includes
cosmic microwave background (CMB)
which is always
since it consists of
photons.
Before ∼ 1.2 Myr,
cosmic neutrino background
probably consisted of
relativistic particles,
and so is considered part of
before that time and certainly up to the
recombination era t = 377,770(3200) y
= 1.192*10**13 s.
See
Wikipedia: Neutrio: Neutrino mass
for summed neutrino mass < 0.3 eV = 300 meV,
Lesgourgue & Verde 2017, p. 3
for z_nr_i = m_i/(0.53 meV) - 1 <∼ 600
and
Nick Gnedin, before or circa 2013,
Cosmological Calculator for the Flat Universe
for t(z=600) = 1.177 Myr for the
Λ-CDM model.
In the modern/local
observable universe,
is negligible as a
mass-energy ingredient.
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