What do the subtle temperature variations (anisotropies) mapped by satellites like WMAP and Planck represent?

Answer

Imprints of density fluctuations in the primordial plasma

These tiny variations in temperature across the sky are the imprints of slight over-densities and under-densities present before decoupling, which acted as gravitational seeds for future structure formation.

What do the subtle temperature variations (anisotropies) mapped by satellites like WMAP and Planck represent?

#Videos

Cosmic Microwave Background Explained - YouTube

OriginuniverseradiationBig Bangcosmic