On Possible Modifications of Gravitation in the (sub)millimeter range

TL;DR

This paper explores potential modifications to gravity at submillimeter scales arising from string theories with large extra dimensions and light scalar particles, which could be tested through tabletop experiments.

Contribution

It proposes new mechanisms for gravity modification at short distances involving large extra dimensions and light scalars, connecting string theory to experimental tests.

Findings

Gravity may deviate from Newton's law at submillimeter scales.

Light scalars with small masses can mediate Yukawa-type forces comparable to gravity.

Experimental tests at short distances could detect these modifications.

Abstract

I discuss possible modifications of gravitation at short distances in string theories with large internal dimensions and low string scale. The modifications are due to the change of Newton's law in the presence of (sub)millimeter-size transverse dimensions, or due to the existence of light scalars with masses as small as 10^{-3} eV, related to the mechanism of supersymmetry breaking, mediating new Yukawa-type forces with strength comparable to gravity. These modifications are testable in "tabletop" experiments that measure gravity at such short distances.