Please cite this paper, and responses to it.
A scientific paper proposes something that may or may not be possible and which must therefore be tested. The most useless thing in the world is one telephone. Likewise, hypotheses do not stand on their own and must be tested, and results of experiments must be reproduced.
This is as good a start as any:
https://en.wikipedia.org/wiki/Falsifiability
It is itself rooted in positivism:
https://en.wikipedia.org/wiki/Positivism
TLDR: There
might be fairies at the bottom of the garden who are very good at hiding, but by hiding so effectively, they may be considered not to exist as they have no observable effect. Any description of the world that excludes fairies and is still thoroughly consistent with observed phenomena is adequate. Like fairies, FTL can be imagined but there is no proven or even proposed practical method for applying it at a 'classical' scale - that is, spaceships rather than quanta (the minimal unit) of information or particles. Thus it remains a
gendanken - useful to generate philosophical discussions, but useless in the most practical sense.