Common empirical basis
Distant sources show systematic redshifts that increase statistically with distance. The CMB, supernovae and large-scale structure all indicate an evolving Universe.
Standard
Until now: standard interpretation
- In the homogeneous expanding model, 1+z = a(t₀)/a(tₑ).
- The shift is usually associated primarily with cosmic expansion between emission and observation.
- Local Doppler and gravitational shifts are included as additional corrections where relevant.
- The standard cosmological model fits a broad data set when dark matter and dark energy are included.
CTPA
CTPA interpretation
- The observed frequency ratio is decomposed into physically distinct contributions rather than assigned to one verbal mechanism.
- In the GR formulation used by CTPA, the gravitational factor is separated from external nongravitational factors; in a static homogeneous medium the gravitational contribution vanishes.
- In Diffusion Gravity, the background scalar-field energy density differs at earlier epochs and changes local proper-time rates.
- The local emission contribution and the redshift accumulated during propagation are considered together; some contributions may compensate.
- The total observed shift should follow from local clock rates, propagation and source motion.
| Criterion | Standard | CTPA |
|---|
| Primary language | Expansion / scale factor | Separate local gravitational, propagation and kinematic contributions |
|---|
| Static homogeneous limit | Not the cosmological case | Gravitational contribution must vanish |
|---|
| Emission | Local Doppler or gravitational correction | DG allows an epoch-dependent contribution through local proper-time rate |
|---|
| Propagation | Encoded in the scale factor | Explicit frequency evolution along the path |
|---|
| Gravity foundation | GR + cosmological matter model | GR + Diffusion Gravity interpretation |
|---|
Possible checks and consequences
Spectra and clocksIndependent atomic transitions must yield the same total observed shift.
Distance–redshiftCompare with supernovae, BAO and other distance indicators.
Early UniverseMaintain consistency with CMB and primordial nucleosynthesis.
The standard interpretation is mainstream. The CTPA decomposition and Diffusion Gravity interpretation are research proposals.