At https://phys.org/news/2023-03-universe-dark-big.html … we have the headline, ‘The universe may have started with a dark big bang’ – but does that mean an invisible explosion? Well, in this instance, the invisibility may not matter. We are told the Big Bang may not have been alone. The appearance of all the particles and radiation in the universe may have been the result of another Big Bang that flooded the universe with dark matter particles. That, presumably was the dark event, the invisible nature of the ionisation process. See ‘Dark Matter and Gravity Waves from a Dark Big Bang’ published on the arXiv pre-print hub – https://doi.org/10.48550/arxiv.2302.11579 ….
the next link is Q Balls – what are they? Read about them at https://phys.org/news/2023-03-astronomers-mysterious-q-balls.html … which begins by telling us ‘our universe may feature large, macr9oscopic, clumps of dark matter known as q-balls ….’ which suggests they are making it up by the minute. The q-balls, we are told, are absolutely invisible – which is why nobody until the team jumped on the idea, had an inkling they were out there lurking in the shadows. However, they may give away their presence via magnification of starlight.
Somewhat bolder, they admit, ‘we do not currently understand the nature of dark matter’ but add, ‘but we do know that it exists.’ This too is on the arXiv preprint server – at