Extinction by grey dust in the intergalactic medium
arXiv:astro-ph/0306459
Abstract
Condensation in the outer regions of decaying supernovae is an efficient source of dust with grain size up to 1 micron. The largest grains leave the parent galaxy, thus forming "grey" intergalactic dust, which can explain the observed dimming of light from distant supernovae without invoking cosmic acceleration
6 pages