Worth noting co-author Avi Loeb produced the headline-making Alien-origin hypothesis paper of a couple of years ago. i.e. context: the paper summarised in the

Worth noting co-author Avi Loeb produced the headline-making Alien-origin hypothesis paper of a couple of years ago. i.e. context: the paper summarised in the OP is his counter to a "hydrogen iceberg" challenge/alternative to his original "alien" paper. https://www.wikipedia.org/wiki/Avi_Loeb#%CA%BBOumuamua https://www.wikipedia.org/wiki/Avi_Loeb#%CA%BBOumuamua