Cosmological bounds on spatial variations of physical constants

Cosmological Bounds on Spatial Variations of Physical Constants

We place strong observational limits on any possible large-scale spatial variation in the values of physical ’constants’ whose space-time evolution is driven by a scalar field. The limits are imposed by the isotropy of the microwave background on large angular scales in theories which describe space and time variations in the fine structure constant, α, the electronproton mass ratio, μ, and the...

Cosmological Variability of Fundamental Physical Constants

The Local Effects of Cosmological Variations in Physical ’Constants’ and Scalar Fields I. Spherically Symmetric Spacetimes

We apply the method of matched asymptotic expansions to analyse whether cosmological variations in physical ‘constants’ and scalar fields are detectable, locally, on the surface of local gravitationally bound systems such as planets and stars, or inside virialised systems like galaxies and clusters. We assume spherical symmetry and derive a sufficient condition for the local time variation of t...

Today’s Cosmological Constants

Knowledge of the constants that describe the current cosmological world model, H0, t0, and the three Ωs is central to physical cosmology. Although there is a vast range of suggested tests and existing constraints much of the recent discussion of cosmological constants involves three time variable photospheres: Cepheids, SNIa, and the CMB last scattering surface. These concluding remarks for the...

Bounds on connective constants of regular graphs

Bounds are proved for the connective constant μ of an infinite, connected, ∆-regular graph G. The main result is that μ ≥ √ ∆− 1 if G is vertex-transitive and simple. This inequality is proved subject to weaker conditions under which it is sharp.