Effects of a decaying cosmological term on the formation of molecules and first objects

We investigate formation of molecules and first objects in a model with a decaying cosmological term (DCT). In particular, we show how the formation of important molecules such as H₂ and HD is influenced during the epoch of the redshift z from 10⁴ to 1. We find that for a phenomenological DCT molecular formation is significantly shifted to the earlier epoch by Δz ∼ 10³ compared to the case in the standard big bang cosmology, as a result of the rapid decrease in the matter temperature. The mass of first objects is estimated using the timescales relevant to their formation. We suggest that the formation scenarios of the objects studied so far could be revised if a DCT is taken into account.