Magnitude and causes of outspiral period derivatives in AM CVns

Determine whether the orbital period derivative during the outspiraling phase of AM Canum Venaticorum evolution is significantly larger than model predictions, and identify the physical reasons underlying any such discrepancy.

Background

Population-level comparisons indicate tension between observed inspiral/outspiral ratios and evolutionary model predictions, hinting that outspiral phases may differ from expectations.

The authors propose that our understanding of outspiral may be incomplete and suggest that outspiral period derivatives could be larger than expected, with the causes currently unknown.