Craig J. Hogan
Professor and Chair, Department of Astronomy
Professor of Physics
University of Washington
 

The universe earlier than a cosmic age of about one second was opaque to all forms of
radiation except gravitational waves; electromagnetic and weak interactions thermalize to equilibrium
distributions and erase information about earlier events. Violent events at earlier times would however have
generated a lingering stochastic background of gravitational waves, at amplitudes and frequencies which
may become observable during the next decade. Possible sources for such a background will be reviewed,
including symmetry breaking during the formation of our three-dimensional "brane" within  a space
of higher dimensionality. Detection strategies will be outlined, including ways to
distinguish instrument noise from primordial gravitational noise.