Massive de Sitter superhorizon scalar mode ($\nu =\sqrt{9/4-m^2/H^2}$)

In the de Sitter approximation, a canonically rescaled scalar has superhorizon powers $(-\tau {)}^{1/2\pm \nu }$. The physical field has powers $(-\tau {)}^{3/2\pm \nu }$. For $H^2<m^2<2H^2$, both physical branches decay, while the slower rescaled branch grows. The generic late-time dimensionless power spectrum is proportional to $(k/(aH){)}^{3-2\nu }$.