The Coevolution of Supermassive Black Holes and Galaxies Since the
    First Billion Years, as Seen Through Gravitational Lensing

    By now it appears that all big galaxies and some
    dwarf ones harbor a supermassive black hole at
    their center, and that the black hole masses correlate
    strongly with their host properties (bulge mass, stellar
    velocity dispersion).  Today, these correlations are
    underpinnings for the hypothesis that massive galaxy
    evolution may be regulated by AGN feedback.
    Observationally, a clear direction is to extend the
    study of the important scaling relations back to earlier
    times when black holes and galaxies were still actively
    forming.  However, the task is very difficult.  I will
    summarize current observational efforts, and show
    how gravitational lensing has been a valuable
    tool toward this goal.  Through lensing and other
    techniques, there is circumstantial evidence that black
    holes may have been more fully grown at earlier times
    compared to their host galaxy bulges, with the galaxies
    playing catch-up.  I will discuss current theoretical
    predictions, and discuss how on-going ground and
    space-based work in lensing will help to improve on
    existing observational uncertainties.