Hellings and Downs curve

== English == === Alternative forms === Hellings-Downs curve === Etymology === Named after R.W. Hellings and G.S. Downs, who first calculated it. === Noun === Hellings and Downs curve (plural Hellings and Downs curves) (astronomy) A graph of the expected correlation of timing effects on pulsars due to cosmological gravitational waves, as a function of angle of separation of the pulsars.