Comparison between solar activity and planetary torque in the frequency domain. a) Fourier spectrum of the solar activity quantified by the solar modulation potential φ. b) Fourier spectrum of the annually averaged torque modulus |N(t)| (blue corresponds to case 1, red to case 2, and green to case 3). The spectra display significant peaks with very similar periodicities: the 88 yr Gleissberg and the 208 yr de Vries cycles are the most prominent, but periodicities around 104 yr, 150 yr, and 506 yr are also seen.