On Tunnelling In Two-Throat Warped Reheating

We consider the energy transfer necessary for the warped reheating scenario in a two-throat geometry. We study KK mode wavefunctions of the full two-throat system in the Randall–Sundrum (RS) approximation and find that wavepacket tunnelling is suppressed unless the Standard Model throat is very long. Nevertheless, wavefunctions of modes localized in different throats have a non-zero overlap and energy can be transferred between the throats by interactions between such KK modes. We calculate the corresponding decay rates and find that they are faster than the tunnelling rates found in previously published works. Next we look at the effects of the imaginary parts of the mode frequencies, induced by the decay, on the calculation of the decay rates themselves, and find that while the self-consistent decay rate can be significantly lower than the naive one, even the improved decay rate is fast enough to ease the phenomenological constraints on the model that were derived previously. Lastly, we discuss mechanisms that may enhance the energy transfer between the throats over the RS rates. In particular, we study models in which the warp factor changes in the UV region less abruptly than in the RS model, and find that it is easy to build phenomenological models in which the plane wave tunnelling rate, and hence the KK mode interaction rates, are enhanced compared to the standard RS setup.