Strong-field QED effects on polarization states in dipole and quadrudipole pulsar emissions Dong-Hoon Kim, Chul Min Kim and Sang Pyo Kim Eur. Phys. J. C, 84 12 (2024) 1322 Published online: 26 December 2024 DOI: 10.1140/epjc/s10052-024-13662-0