Cosmology and the Standard Model

TL;DR

This paper explores a multiverse model where universe properties depend on size, suggesting life-supporting conditions are limited to universes within a specific size range, and discusses implications for cosmology and particle physics.

Contribution

It proposes a model linking universe size to physical properties and life support, providing new insights into multiverse implications for cosmology and particle physics.

Findings

Universes with size within a factor of ~1.4 of ours may support life.

Universe properties vary with size based on assumed parameter dependence.

The model offers a framework for understanding cosmological and particle physics problems.

Abstract

We consider the properties of an ensemble of universes as function of size, where size is defined in terms of the asymptotic value of the Hubble constant (or, equivalently, the value of the cosmological constant). We assume that standard model parameters depend upon size in a manner that we have previously suggested, and provide additional motivation for that choice. Given these assumptions, it follows that universes with different sizes will have different physical properties, and we estimate, very roughly, that only if a universe has a size within a factor of a square root of two or so of our own will it support life as we know it. We discuss implications of this picture for some of the basic problems of cosmology and particle physics, as well as the difficulties this point of view creates.