Astrophysical Constraints on Large Extra Dimensions

TL;DR

This paper investigates how astrophysical phenomena like supernovae constrain theories with large extra dimensions, setting lower bounds on the string scale based on energy loss via graviton emission.

Contribution

It provides new astrophysical bounds on the string scale in models with large extra dimensions by analyzing energy-loss mechanisms in stellar environments.

Findings

Lower limit on string scale M_S > 30-130 TeV from SN1987A

Constraints depend on the number of extra dimensions (2 or 3)

Energy-loss rates from various processes are used to derive bounds.

Abstract

In the Kaluza-Klein (KK) scenario with n large extra dimensions where gravity propagates in the 4+n dimensional bulk of spacetime while gauge and matter fields are confined to a four dimensional subspace, the light graviton KK modes can be produced in the Sun, red giants and supernovae. We study the energy-loss rates through photon-photon annihilation, electron-positron annihilation, gravi-Compton-Primakoff scattering, gravi-bremsstrahlung and nucleon-nucleon bremsstrahlung, and derive lower limits to the string scale M_S. The most stringent lower limit obtained from SN1987A leads to $M_S> 30 - 130$ TeV (2.1-9.2 TeV) for the case of two (three) large extra dimensions.