SN1987A Constraints on Large Compact Dimensions

TL;DR

This paper uses observations from SN1987A to place constraints on theories with large extra dimensions, finding strong bounds for two extra dimensions but less restrictive limits for three or more.

Contribution

It provides new astrophysical bounds on the size of extra dimensions and the fundamental Planck scale, especially constraining models with two extra dimensions.

Findings

For two extra dimensions, the Planck scale M > 50 TeV.

Radius of extra dimensions R < 0.3 microns for two dimensions.

Constraints are weaker for three or more extra dimensions.

Abstract

Recently there has been a lot of interest in models in which gravity becomes strong at the TeV scale. The observed weakness of gravitational interactions is then explained by the existence of extra compact dimensions of space, which are accessible to gravity but not to Standard Model particles. In this letter we consider graviton emission into these extra dimensions from a hot supernova core. The phenomenology of SN1987A places strong constraints on this energy loss mechanism, allowing us to derive a bound on the fundamental Planck scale. For the case of two extra dimensions we obtain a very strong bound of M > 50 TeV, which corresponds to a radius R < 0.3 microns. While there are a lot of sources of uncertainty associated with this bound, we find that pushing it down to the few-TeV range, which could in principle be probed by ground-based experiments, is disfavored. For three or more extra dimensions the SN1987A constraints do not exclude a TeV gravitational scale.