Anthropic Arguments and the Cosmological Constant, with and without the Assumption of Typicality

We reexamine claims that anthropic arguments provide an explanation for the observed smallness of the cosmological constant, and we argue that correlations between the cosmological constant value and the existence of life could at best be demonstrated only under restrictive assumptions. Causal effects are more subtle to uncover. The assumption of our typicality is crucial to such arguments.

Figure 1

A contour plot of $R$ over the most “favorable” corner of the $(\alpha ,\gamma )$ plane, with fixed $\beta =1$ (left) and $\beta ={10}^{-5}$ (right). The shaded area indicates where $R\ge 0.1$.