The Planetary Theory of Solar Activity Variability: A Review

Commenting the 11-year sunspot cycle, Wolf (1859, MNRAS 19, 85-86) conjectured that "the variations of spot frequency depend on influences Venus, Earth, Jupiter, and Saturn". The high synchronization our planetary system is already nicely revealed by fact ratios orbital radii are closely related to each other through a scaling-mirror symmetry equation (Bank Scafetta, Front. Astron. Space Sci. 8, 758184, 2022). Reviewing many harmonics invariant inequalities characterize motions solar from monthly millennial time scales, we show they not randomly distributed but clearly tend cluster around some specific values also match those main activity cycles. In cases, models have even been able predict time-phase oscillations including Schwabe cycle. We stress based hypothesis regulated its internal dynamics alone never reproduce variety observed Although tidal forces weak, review number mechanisms could explain how structure dynamo get tuned motions. particular, discuss effects weak be significantly amplified in core an induced increase H-burning. Mechanisms modulating electromagnetic gravitational large-scale discussed.