Event Category: 4D Seminar

4D Seminar series:
Monday at 2:30 on campus

The minimal SO(5)/SO(4) linear $\sigma$-model is used as a template for the ultraviolet completion of scenarios in which the Higgs particle is a low-energy remnant of some high-energy dynamics, for instance, if the Higgs has a Goldstone boson parenthood. Varying the $\sigma$ mass allows to sweep from the perturbative regime to the usual non-linear implementations. A complete renormalizable Lagrangian -including … Read More

Abstract: Under time-dependent background, some particles can become light and those particles are produced (in non-perturbative way). Such particle production takes important roles in the early universe because the background is changing during inflation. Also, the relaxion mechanism, a dynamical approach to fine-tuning problem, has a condition that particle production happens. In this talk, I discuss particle production of scalars … Read More

Abstract: Weakly Interacting Massive Particles (WIMPs) have been the main focus of the Dark Matter (DM) community for many years. However, there are both experimental clues and theoretical motivation to think beyond the WIMP paradigm and consider new ideas in the search for DM. I discuss two such new directions. First I explore a new low-threshold direct-detection concept for DM, … Read More

We recast 4D scattering amplitudes and their soft limits as correlators of a 2D CFT on the celestial sphere. Our construction relies on a foliation of 4D flat space into a family of 3D hyperbolic geometries to which the AdS3/CFT2 dictionary is directly applicable. By reformulating 4D scattering amplitudes as 3D Witten diagrams dual to 2D correlators, we show how … Read More

We show that by supplementing the MSSM with vector-like 4th generation copies of standard model fermions we can simultaneously extend the viable mass range of Bino dark matter and alleviate the fine tuning in the Higgs sector. The extra requirement of perturbative gauge coupling unification restricts such models to only two, both of which are consistent with current data in … Read More

The morphology of dark matter annihilation/decay signals offers a handle for discrimination of dark matter against astrophysical backgrounds. Recent advances in N-body simulations allow us to map out the expected distribution of morphological parameters, rather than focusing on a small sample of halos which are assumed to be representative. In this talk, I will use data from the Illustris simulation … Read More