On Observational Predictions from Multidimensional Gravity

TL;DR

This paper explores observational signatures of multidimensional gravity theories, analyzing how conformal frames affect measurable parameters like post-Newtonian coefficients, black hole temperatures, and Coulomb law modifications, with implications for detecting multidimensional objects.

Contribution

It provides a comprehensive analysis of observational effects in multidimensional gravity, emphasizing the role of conformal frames and introducing the concept of T-holes as potential observable entities.

Findings

The Eddington parameters depend on integration constants and vary between bodies.

In the Einstein frame, the parameter gamma always equals 1.

The modified Coulomb law is frame-independent and unaffected by extra dimensions.

Abstract

We discuss possible observational manifestations of static, spherically symmetric solutions of a class of multidimensional theories of gravity, which includes the low energy limits of supergravities and superstring theories as special cases. We discuss the choice of a physical conformal frame to be used for the description of observations. General expressions are given for (i) the Eddington parameters $\beta$ and $\gamma$, characterizing the post-Newtonian gravitational field of a central body, (ii) p-brane black hole temperatures in different conformal frames and (iii) the Coulomb law modified by extra dimensions. It is concluded, in particular, that $\beta$ and $\gamma$ depend on the integration constants and can be therefore different for different central bodies. If, however, the Einstein frame is adopted for describing observations, we always obtain $\gamma=1$. The modified Coulomb law is shown to be independent of the choice of a 4-dimensional conformal frame. We also argue the possible existence of specific multidimensional objects, T-holes, potentially observable as bodies with mirror surfaces.