Importance of disk-driven migration for close-in giants

Ascertain the importance of disk-driven migration in the formation of close-in giant exoplanets by quantifying its role under varying protoplanetary disk conditions relative to alternative migration channels.

Background

Multiple mechanisms could deliver giant planets to short-period orbits, including disk-driven migration and high-eccentricity tidal migration triggered by companions. The relative contribution of each mechanism remains debated in the literature.

The authors emphasize that disk-driven migration’s efficacy depends sensitively on disk properties and that its overall importance for producing close-in giants is uncertain, highlighting a broader, field-level unresolved question.

References

The details of disk-driven migration are highly sensitive to the disk conditions, and hence it is not clear how important this migration is for the formation of close-in giants \citep[e.g.][]{2014prpl.conf..667B,2021JGRE..12606629F}.

— TOI-6038 A b: A dense sub-Saturn in the transition regime between the Neptunian ridge and savanna  (2501.02272 - Baliwal et al., 4 Jan 2025) in Section “Formation and evolution scenarios”

However, no single model can satisfactorily account for all the observational evidence, and the formation pathway of hot Jupiters remains an open question.

— Are Hot Jupiters Tidally Disrupted During Stellar Main Sequence?  (2608.12790 - Hu et al., 13 Aug 2026) in Section 1, Introduction