We present new upper and lower bounds to the primordial abundances of deuterium and 3He based on observational data from the solar system and the interstellar medium. Independent of any model for the primordial production of the elements we find (at the 95% C.L.): 1.5 × 10-5 ≤ (D/H)P ≤ 10.0 × 10-5 and (3He/H)P ≤ 2.6 × 10-5. When combined with the predictions of standard big bang nucleosynthesis, these constraints lead to a 95% C.L. bound on the primordial abundance deuterium: (D/H)best = (3.5-1.8+2.7) × 10-5. Measurements of deuterium absorption in the spectra of high-redshift QSOs will directly test this prediction. The implications of this prediction for the primordial abundances of 4He and 7Li are discussed, as well as those for the universal density of baryons.
- Elementary particles
- ISM: abundances
- Nuclear reactions, nucleosynthesis, abundances
- Solar system: general