What is recorded here?
Jimenez, Verde, Treu and Stern used the upper age envelope of selected SDSS galaxies to estimate the low-redshift expansion rate, finding H₀ = 69 ± 12 km s⁻¹ Mpc⁻¹ in their 2003 analysis. Simon, Verde and Jimenez subsequently combined selected galaxy spectra, including previously analyzed objects and new survey data, to estimate H(z) at nine redshifts and fit a parameterized dark-energy potential; the resulting potential was consistent with a constant within the stated uncertainties.
Source-linked catalogue note. A detailed explanatory guide has not yet been prepared for this entry.
Scientific scope
Stellar ages depend on population-synthesis fits, passive-evolution assumptions and galaxy selection, not direct clocks. The 2003 low-redshift fit extends to z = 0.17 at effective z = 0.09 and uses an approximately 4% extrapolation to H₀ in its reference cosmology. The later work reuses earlier galaxy data and the earlier low-redshift determination; the two are not independent detections. Its galaxy sample is small, and dark-energy potential reconstruction assumes spatial flatness, chosen parameterization and matter-density priors. Consistency with a constant potential does not exclude evolution. Forecasts for future surveys are not achieved results.
Read the original work
- Constraints on the equation of state of dark energy and the Hubble constant from stellar ages and the CMB
- Constraints on the redshift dependence of the dark energy potential
This English explanation is an editorial reading view. It does not replace the complete original work or certify its science.
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People and systems
Raul Jimenez; Licia Verde; Tommaso Treu; Daniel Stern; Joan Simon
These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.
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English catalogue narrative
Galaxy ages trace the cosmic expansion history
Jimenez, Verde, Treu and Stern used the upper age envelope of selected SDSS galaxies to estimate the low-redshift expansion rate, finding H₀ = 69 ± 12 km s⁻¹ Mpc⁻¹ in their 2003 analysis. Simon, Verde and Jimenez subsequently combined selected galaxy spectra, including previously analyzed objects and new survey data, to estimate H(z) at nine redshifts and fit a parameterized dark-energy potential; the resulting potential was consistent with a constant within the stated uncertainties.
Scientific scope
Stellar ages depend on population-synthesis fits, passive-evolution assumptions and galaxy selection, not direct clocks. The 2003 low-redshift fit extends to z = 0.17 at effective z = 0.09 and uses an approximately 4% extrapolation to H₀ in its reference cosmology. The later work reuses earlier galaxy data and the earlier low-redshift determination; the two are not independent detections. Its galaxy sample is small, and dark-energy potential reconstruction assumes spatial flatness, chosen parameterization and matter-density priors. Consistency with a constant potential does not exclude evolution. Forecasts for future surveys are not achieved results.
Reading status
This is a source-linked WRS catalogue note. A full explanatory guide and independent scientific reconstruction have not been completed for this entry. Read the identified original work for its complete narrative and arguments.
People and systems
Raul Jimenez; Licia Verde; Tommaso Treu; Daniel Stern; Joan Simon
These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.