1208.3563 (Tetsutaro Higaki et al.)

Dark Radiation and Dark Matter in Large Volume Compactifications    [PDF]

Tetsutaro Higaki, Fuminobu Takahashi

We argue that dark radiation is naturally generated from the decay of the overall volume modulus in the LARGE volume scenario. In this model, the main component of dark radiation is the axionic superpartner of the modulus. We find that the modulus decay through the Giudice-Masiero term gives the dominant contribution to the total decay rate. The decay pattern of the overall volume modulus can be understood in terms of the mixing with a conformal compensator field; the modulus is coupled to the violation of the scale invariance, and in particular, it decays into the standard model gauge bosons through the superconformal anomaly. Furthermore, we find that the lightest supersymmetric particles produced by the modulus decay can naturally account for the observed dark matter density.

View original: http://arxiv.org/abs/1208.3563