Is the Cosmological Constant Non-Zero?

Summary

Clearly more data are needed for both the CBR Doppler peak and the high-Z supernovae. Fortunately both are expected in the forseeable future.

The current analyses favor Ω_Λ ≃ 0.7 and Ω_m ≃ 0.3.

Of course, Λ is still 120 orders of magnitude below its natural value, and 52 orders of magnitude below (250 GeV)⁴ and that theoretical issue remains.

The non-zero Λ implies that we live in a special cosmic era: Λ was negligible in the past but will dominate the future giving exponential growth R~e ^λt, t→∞. This cosmic coincidence is addressed by quintessence.

The principal point of our own work in [19] is that the value of l ₁ depends almost completely only on the geometry of geodesics since recombination, and little on the details of the accoustic waves, since our iso-l ₁ plot agrees well with the numerical results of White et al. [26].