Tests of CPT invariance in gravitational waves with LIGO-Virgo catalog GWTC-1 Sai Wang and Zhi-Chao Zhao Eur. Phys. J. C, 80 11 (2020) 1032 Published online: 08 November 2020 DOI: 10.1140/epjc/s10052-020-08628-x