Testing CPT Symmetry with Current and Future CMB Measurements

Understand

In this paper we use the current and future cosmic microwave background (CMB) experiments to test the Charge-Parity-Time Reversal (CPT) symmetry.

• We consider a CPT-violating interaction in the photon sector $\mathcal{L}_{\rm cs}\sim p_\mu A_\nu \tilde{F}^{\mu\nu}$ which gives rise to a rotation of the polarization vectors of the propagating CMB photons.
• By combining the nine-year WMAP, BOOMERanG 2003 and BICEP1 observations, we obtain the current constraint on the isotropic rotation angle $\bar{\alpha} = -2.12 \pm 1.14$ ($1\sigma$), indicating an about $2\sigma$ significance of the CPT violation.
• Here, we particularly take the systematic errors of CMB measurements into account.