ON THE GAUSS-BONNET GRAVITY

摘要

We argue that propagation of the gravitational field in the extra dimension ismotivated by physical realization of second iteration of self interaction of gravity and it is described by the Gauss-Bonnet term. The most remarkable feature of Gauss-Bonnet gravity is that at high energy it radically transforms radial dependence from inverse to proportionality as the singularity is approached and thereby makes it weak. A similar changeover also occurs in the approach to the singularity in loop quantum gravity. It is analogous to Planck's law of radiation where a similar change occurs for high and low energy behavior. This is how it seems to anticipate in qualitative terms and in the right sense the quantum gravity effect in 5 dimensions where it is physically non-trivial. The really interesting question is, could this desirable feature be brought down to the 4-dimensional spacetime by dilatonic coupling to the Gauss-Bonnet term or otherwise?