The Universe as a Diffusive Medium -- Constraining or Detecting the   Gravitational Wave Background
  We calculate the ``seeing'' effect on distant sources due to a gravitational wave background. We derive the limit in strain and energy density of the gravitational wave based on the limit of detectability of this effect with the present day telescope resolution. We also compare our detection limit to those obtained from existing methods. 
Francine Marleau and Glenn Starkman