Concatenation of scales below 1 eV

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