Virtual matter can not give off photons - it would violate conservation of momentum (unless it was in pairs, but that would not work with Cherenkov radiation).
There seems to be one paper about Cherenkov radiation in a vacuum [1]. But I have only read the abstract. So you are probably right, that there's no Cherenkov radiation in a vacuum. Or does anyone has any better knowledge?
[1] "Cherenkov radiation in vacuum and plasma-filled microwave sources in the absence of guiding magnetic fields" by GS Nusinovich
Comments
Only virtual matter.
Which should still give off Cerenkov radiation in the old, boring way, even without tachyons.
Virtual matter can not give off photons - it would violate conservation of momentum (unless it was in pairs, but that would not work with Cherenkov radiation).
There seems to be one paper about Cherenkov radiation in a vacuum [1]. But I have only read the abstract. So you are probably right, that there's no Cherenkov radiation in a vacuum. Or does anyone has any better knowledge?
[1] "Cherenkov radiation in vacuum and plasma-filled microwave sources in the absence of guiding magnetic fields" by GS Nusinovich