Cosmological birefringence due to CPT-even Chern–Simons-like term with Kalb–Ramond and scalar fields Shih-Hao Ho, W. F. Kao, Kazuharu Bamba and C. Q. Geng Eur. Phys. J. C, 75 5 (2015) 192 Published online: 05 May 2015 DOI: 10.1140/epjc/s10052-015-3426-5