Speakers
Description
The diffeomorphism invariance of a compactified five-dimensional theory of gravity is spontaneously broken by the background space-time geometry. In this talk we discuss the surprising properties of the scattering amplitudes of the massive spin-2 Kaluza-Klein modes of these theories, and explain the origin of these properties in terms of underlying hidden symmetries.
We revisit dark-matter (DM) models within radius stabilized Randall-Sundrum models. Specifically we consider models where the dark matter candidates are Standard Model (SM) singlets confined on the TeV brane, and interact with the SM via the spin-2 Kaluza-Klein (KK) modes and through spin-0 Goldberger-Wise modes. By taking into account relic-density, latest collider constraints and direct detection into account, we show that the spin-2 KK portal DM models are highly constrained. In particular we show that within the usual thermal freeze-out scenario, scalar and fermion dark matter models are ruled out, while vector dark matter models are still viable for a certain region of parameter space. We point out the relevance of the massive radion in these models, and show that radion mediated annihilation play a significant role in evading the constraints.
