Circular Polarization of Gravitational Waves from Early-Universe Helical Turbulence

Understand

We perform direct numerical simulations to compute the net circular polarization of gravitational waves from helical (chiral) turbulent sources in the early Universe for a variety of initial conditions, including driven (stationary) and decaying turbulence.

• We investigate the resulting gravitational wave signal assuming different turbulent geneses such as magnetically or kinetically driven cases.
• Under realistic physical conditions in the early Universe we compute numerically the wave number-dependent polarization degree of the gravitational waves.
• We find that the spectral polarization degree strongly depends on the initial conditions.