Sometimes size does not matter

Understand

Cosmological fine-tuning has traditionally been associated with the narrowness of the intervals in which the parameters of the physical models must be located to make life possible.

• A more thorough approach focuses on the probability of the interval, not on its size.
• Most attempts to measure the probability of the life-permitting interval for a given parameter rely on a Bayesian statistical approach for which the prior distribution of the parameter is uniform.
• However, the parameters in these models often take values in spaces of infinite size, so that a uniformity assumption is not possible.