Concatenation of Scales Below 1 eV

Abstract

There are (at least) four numbers of physical and cosmological significance whose inferred values, when expressed in mass units, cluster in a window below 1 eV. These are: the neutrino mass, the neutrino chemical potential, the cosmological constant, and the size of two extra dimensions (if the fundamental scale of gravity is 1-10 TeV). In this note, we imagine ways in which these four numbers could all be connected.