High-precision nuclear chronometer for the cosmos

TL;DR

This paper introduces the Th-U-X nuclear chronometer, a new method for estimating stellar ages with high precision, reducing uncertainties and aligning well with cosmic microwave background estimates.

Contribution

The paper proposes the Th-U-X chronometer, which improves age estimation accuracy by constraining astrophysical conditions and reducing uncertainties in nuclear cosmochronology.

Findings

Reduces age uncertainty from over 2 billion to 0.3 billion years.

Provides stellar age estimates compatible with the cosmic microwave background.

Contradicts the younger cosmic age derived from gravitational lensing.

Abstract

Nuclear chronometer, which predicts the ages of the oldest stars by comparing the present and initial abundances of long-lived radioactive nuclides, provides an independent dating technique for the cosmos. A new nuclear chronometer called Th-U-X chronometer is proposed, which imposes stringent constraints on the astrophysical conditions in the $r$-process simulation by synchronizing the previous Th/X, U/X and Th/U chronometers. The astrophysical uncertainties of nuclear chronometer are significantly reduced from more than $\pm2$ billion years to within 0:3 billion years by the Th-U-X chronometer. The proposed chronometer is then applied to estimate the ages of the six metal-poor stars with observed uranium abundances, and the predicted ages are compatible with the cosmic age 13.8 billion years predicted from the cosmic microwave background radiation, but in contradictory with the new cosmic age 11.4 billion years from the gravitational lenses measurement.