Multiple gravitational actions in multimetric gravity

by Mr Kevin Croker (UH Physics)

Monday Dec 9, 2013, 3:30 PM → 4:30 PM Pacific/Honolulu

417A (WAT)

In the setting of Einstein-like gravity with multiple metric tensors, it is argued that the appropriate generalization of universal coupling requires revision to the canonical model-building formalism. In particular, we argue that geometric consistency in the context of multiple metrics precludes consideration of a single action from which all dynamical fields are determined. We present a toy two-action model exhibiting mathematical features previously overlooked and exhibit a non-trivial solution set. We then apply the toy model to the core/cusp problem of galactic dark matter halos and extract experimental predictions via a successive approximation scheme. In particular, observers bound to a Minkowski metric encounter a pseudo-isothermal sphere profile with well-behaved temporal growth. The model is easily fit to observation and predicts a simple algebraic dependence between previously phenomenological fit parameters core radius $R_C$ and central density $\rho_0$ of pseudo-isothermal fits.