A radiative decaying big bang relic with a mass at the eV scale, which we dub “blue axion,” can be probed with direct and indirect observations of the cosmic optical background (COB). The strongest bounds on blue-axion cold dark matter come from the Hubble Space Telescope (HST) measurements of COB anisotropies at 606 nm. We suggest that new HST measurements at higher frequencies (336 nm and...
The QCD axion is a well-motivated extension of the Standard Model which dynamically relaxes away strong CP violation. However, to date most searches for the axion have instead focused on its model-dependent coupling to photons. I will present a new idea for axion detection that directly targets its defining coupling to gluons, by resonantly amplifying the oscillating currents from time-varying...
Dark matter (DM) consisting of weakly interacting massive particles (WIMPs) self-annihilates into baryonic matter and provides a possibility for indirect detection. We observe dwarf spheroidal galaxies (dSph) because they are rich in DM but baryonic emissions are low. In the magnetic field of dSph, the particles produced in DM self-annihilation emit synchrotron radiation which peaks at low...
