Cole Miller's research in the last few years has focused on theory and modeling of high-energy radiation from neutron stars and black holes. Data interpreted using his theoretical models have provided the first evidence for the existence of an innermost stable circular orbit around neutron stars and black holes (a key prediction of strong-gravity general relativity) and evidence for a 2.3 solar mass neutron star, which constrains strongly the equation of state of matter at high densities. His interests also extend beyond compact objects, to subjects such as the use of gravitational lensing to study different classes of cosmological sources. He has used lensing to place limits on the average redshift of gamma-ray bursts and to constrain dark energy parameters based on observations in the Hubble Deep Field. He has also investigated the effects of accretion by primordial compact objects on the power spectrum of the cosmic microwave background. In particular, he has placed limits on the contributions of such objects to dark matter and on the degree to which ionization from accretion can be used to explain the weakness of the second acoustic peak as observed with BOOMERanG. Most recently, he has collaborated with Doug Hamilton on models of intermediate-mass black holes and their implications for graviational radiation.