UC Riverside

We present four dark sector models with novel phenomena beyond the weakly-interacting massive particle paradigm. We present a model of spin-1 dark matter charged under a U1) gauge symmetry, resulting from the spontaneous symmetry breaking of an SU(2) dark sector. The dark matter is subject thermal freeze out and direct detection constraints while simultaneously meeting self-interaction targets for small scale structure anomalies. We present a model of pseudo-Goldstone boson dark matter based of the same symmetry structure. The pseudo-Goldstone boson dark matter satisfies thermal freeze out and direct detection constraints while satisfying self-interaction targets as well. We expand the self-interacting dark matter framework to the case of a continuum of mediators and present a model of continuum-mediated self-interacting dark matter. The model is described holographically by brane localized dark matter interacting with a bulk scalar in a slice of 5D anti-de Sitter space. The long-range scattering potential follows a non-integer power law, resulting in a self-scattering cross section that depends on a non-integer power of the dark matter relative velocity as well as Sommerfeld enhancement which exhibits a pattern of resonances determined by the non-integer power. The novel power laws introduced by the continuum mediator present new possibilities self-interacting dark matter phenomenology. We expand the dark photon framework to the case where the dark photon is a continuum of states, modeled as a bulk spin-1 field interacting with brane-localized matter in a 5D slice of anti-de Sitter space. We derive a simple formula for recasting existing dark photon bounds for our model. We consider a model of brane-localized dark matter which freezes out by annihilating into holographic dark photons, and present targets for the dark matter mass and coupling to the holographic dark photon. We conclude that even though a definitive signal for dark matter remains unseen, there are several possibilities for model building and future study which may provide further insight into the microscopic nature of dark matter.