New Constraints On Cosmic Polarization Rotation Including SPTpol B-mode   Polarization Observations
  We present an update of the cosmic polarization rotation (CPR) constraint from the recent SPTpol measurements of sub-degree B-mode polarization in the cosmic microwave background (CMB) of 100 square degrees of sky. Our previous CPR fluctuation constraint from the joint ACTpol-BICEP2-POLARBEAR polarization data is 23.7 mrad (1.36{\deg}). With new SPTpol data included, the CPR fluctuation constraint is updated to 17 mrad (1{\deg}) with the scalar to tensor ratio r = - 0.05 +- 0.1 
W.-P. Pan, S. di Serego Alighieri, W.-T. Ni, L. Xu
astro-ph.CO gr-qc hep-ph