Electronic International Standard Serial Number (EISSN)
1572-9532
abstract
The article The space of light rays: Causality and L-boundary, written by A. Bautista, A. Ibort and J. Lafuente, was originally published online on17 June 2022 with Open Access under Creative Commons Attribution (CC BY) licence 4.0. After publication in volume 54, issue 6, 59 the author(s) decided to cancel the Open Access. Therefore, the copyright of the article has been changed on 2 September 2022 to (copyright) Springer Science + Business Media, LLC, part of Springer Nature 2022 with all rights reserved.