From diffuse extragalactic and galactic gamma-rays to limits on extra dimensions

Abstract

ABSTRACT We derive the maximum fraction of energy emitted in the form of massive (Kaluza–Klein) gravitons by core collapse supernovae, and the corresponding minimal extra-dimensional Planck mass M* in the ADD gravity framework at TeV scales. Our constraints arise (a) from the extragalactic gamma-ray background observed by Fermi-LAT after astrophysical sources have been removed and (b) via the residual galactic emission left after astrophysical and potentially dark matter emission have been removed. We focus on a number of extra dimensions 3 and 4, since M* is then in the TeV range, where astrophysical and collider constraints compete. Lower limits on M* are derived in the case (a) of 8.0 and 1.1 TeV for n = 3 and n = 4, respectively, and in the case (b) of 16 and 1.9 TeV. These limits are especially robust and insensitive to the various uncertainties involved.