Assess gravitational-wave signatures from the mixed gauge–gravitational chiral anomaly in the Early Universe

Investigate whether the mixed gauge–gravitational chiral anomaly can generate circularly polarized gravitational waves in the Early Universe, for example around the electroweak phase transition, and characterize the predicted observational signatures of such emission.

Background

Chiral-anomaly-driven processes, including chiral magnetic instability and magnetogenesis, have been proposed to operate in the Early Universe, potentially leading to large-scale helical magnetic fields.

Building on these ideas, the authors highlight an unresolved issue: whether the mixed gauge–gravitational anomaly could also source circularly polarized gravitational waves, implying a new cosmological signature of anomaly-induced dynamics.