Abstract: Utilizing the Fermi measurement of the gamma-ray spectrum toward the Galactic Center, we derive some of the strongest constraints to date on the dark matter (DM) lifetime in the mass range from hundreds of MeV to above an EeV. Our profile-likelihood based analysis relies on 413 weeks of Fermi Pass 8 data from 200 MeV to 2 TeV, along … Read More

I will present the effective theory of a generic class of hidden sectors where supersymmetry is broken together with an approximate R-symmetry at low energy. The light spectrum contains the gravitino and the pseudo-Nambu-Goldstone boson of the R-symmetry, the R-axion. I will discuss model independent constraints on the R-axion decay constant for R-axion masses ranging from GeV to TeV which … Read More

Abstract: “In this talk I will propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles, rather than from Boltzmann suppression. The relic abundance is set … Read More

The origin of the asymmetry between matter and anti-matter of the Universe remains one of the most important open questions in particle physics and cosmology. We propose a novel mechanism, the lepto-bubbles mechanism, to dynamically generate this observed asymmetry. The particle that undergoes the phase transition is a SM-singlet scalar which couples to the lepton number violating Weinberg dimension-5 operator. … Read More

Galaxy clusters represent excellent laboratories to search for Axion-Like Particles (ALPs). They contain magnetic fields which can induce quasi-sinusoidal oscillations in the X-ray spectra of AGNs situated in or behind them. Ultra-deep Chandra observations of the Perseus cluster contain over 5 x 105 counts from the central NGC1275 AGN, and represent an extraordinary dataset for ALP searches. In this talk … Read More

Abstract: Galaxies and galaxy clusters outside the Milky Way are expected to be some of the brightest sources of dark matter (DM) annihilation in the sky. Further, galaxy catalogs such as the 2MASS survey tell us where thousands of these objects are located. The challenge, however, is that catalogs only detail the baryonic properties of individual galaxies rather than the … Read More

Abstract: Given the lack of conventional SUSY signals in the LHC data, a more complicated story may be required to explain weak scale physics. I will present a class of natural models which ensure the one-loop divergences in the Higgs mass are cancelled. The top partners are not related by an internal symmetry of the Lagrangian, but instead the symmetry … Read More