Cosmological continuity and constant-w density scaling
Research context
research method · conditional · As of 2026-10-10
For an independently conserved homogeneous component with constant equation-of-state w, density scales with a as a^-3(1+w).
Key knowledge
For an independently conserved homogeneous component with constant equation-of-state w, density scales with a as a^-3(1+w). Here density is mass-equivalent density, so pressure appears divided by c², matching the Ark's existing Friedmann convention.
Values and equations
dρ/dt+3H(ρ+p/c^2)=0; p=wρc^2; ρ=ρ0(a/a0)^[-3(1+w)]
- ρ,ρ0
- Mass-equivalent density kg m^-3
- p
- Pressure Pa
- w
- Constant equation-of-state parameter 1
- H
- Expansion rate s^-1
- a,a0
- Scale factors 1
- c
- Speed of light m s^-1
Conditions and scope
- GR homogeneous FLRW component; interactions, varying w and bulk effects need an extended continuity equation.
- a is dimensionless and normalized at a declared epoch; do not mix energy-density and mass-density conventions.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Cosmology: the expanding universe: Sections 1.2–1.3: continuity and component expansion solutions (selected source body inspected).
2026-10-10 · Bounded source check of the recorded statement and conditions. This does not certify a unique physical model, reproduce the cited study or replace independent branch review.
Entry details
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- research-earth-component-continuity
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference