Relativistic longitudinal self-compression of ultrashort time-domain hollow Gaussian pulses in plasma Xiaochao Cao, Feiyun Fang, Zhaoying Wang and Qiang Lin Eur. Phys. J. D, 71 10 (2017) 256 Published online: 17 October 2017 DOI: 10.1140/epjd/e2017-80205-8