Theory Division

The Randall-Sundrum model with two branes (RS1)  is a gravitational theory on five-dimensional spacetime. Because its fifth dimension is compactified, the theory manifests as a four-dimensional theory at low energies, where it describes interactions among a Kaluza-Klein spectrum that contains a 4D graviton, massless radion, and infinitely many massive spin-2 states. These massive spin-2 states pose... More »

We consider a minimal extension of the Standard Model with a hidden sector charged under a dark local U(1)’ gauge group, accounting simultaneously for light neutrino masses and the observed Dark Matter relic abundance. The model contains two copies of right-handed neutrinos which give rise to light neutrino-masses via an extended seesaw mechanism. The presence... More »