Instead they can be created by two mechanisms: the first one is by gravitational lensing of E-modes, which has been measured by the South Pole Telescope in 2013; the second one is from gravitational waves arising from cosmic inflation.
Instead they can be created by two mechanisms. The first one is by gravitational lensing of E-modes. Gravitational lensing of E-modes has been measured by the South Pole Telescope in 2013. The second one is from gravitational waves. These gravitational waves are arising from cosmic inflation.