Tag: ISW

Cool spots on the CMB

A confirmation of the cooling power of voids

The standard cosmological model predicts that photons will heat up slightly while crossing the strong gravitational potential of a massive cluster of galaxies. Conversely, while crossing a void – a region of space empty of galaxies – photons will cool down. On large scales of hundreds of megaparsecs the effect is due to the accelerating expansion rate of space and…