Three in one go: consequential angular momentum loss can solve major problems of CV evolution

TL;DR

This paper proposes that consequential angular momentum loss, increasing with decreasing white dwarf mass, can resolve major discrepancies in cataclysmic variable evolution, including white dwarf mass and orbital period distribution.

Contribution

It introduces a new model of CAML that explains observed white dwarf masses and orbital period distributions in CVs, aligning theory with observations.

Findings

CAML increases with decreasing WD mass.

Model matches observed WD mass distribution.

Model aligns with observed CV orbital periods and space density.

Abstract

The average white dwarf (WD) masses in cataclysmic variables (CVs) have been measured to significantly exceed those of single WDs, which is the opposite of what is theoretically expected. We present the results of binary population synthesis models taking into account consequential angular momentum loss (CAML) that is assumed to increase with decreasing WD mass. This approach can not only solve the WD mass problem, but also brings in agreement theoretical predictions and observations of the orbital period distribution and the space density of CVs. We speculate that frictional angular momentum loss following nova eruptions might cause such CAML and could thus be the missing ingredient of CV evolution.