16 research outputs found
Effective Lagrangians for physical degrees of freedom in the Randall-Sundrum model
We derive the second variation Lagrangian of the Randall-Sundrum model with
two branes, study its gauge invariance and diagonalize it in the unitary gauge.
We also show that the effective four-dimensional theory looks different on
different branes and calculate the observable mass spectra and the couplings of
the physical degrees of freedom of 5-dimensional gravity to matter.Comment: 22 pages, LaTeX, typos correcte
The variation of the gravitational constant inferred from the Hubble diagram of Type Ia supernovae
We consider a cosmological model with a variable gravitational constant, G,
based on a scalar-tensor theory. Using the recent observational data for the
Hubble diagram of type Ia supernovae (SNeIa) we find a phenomenological
expression describing the variation of G. The corresponding variation of the
fine structure constant \alpha within multidimensional theories is also
computed and is shown not to support known constraints on \Delta \alpha /
\alpha.Comment: LaTeX, 12 pages, 3 figs. In the replaced version figures are added
and some errors are correcte