Dark Flow

[darkmatter4brains]

Does anybody know the current status on this idea of Dark Flow. I thought it was discredited, or at least, cast into some doubt.

However, I just watched a show dated to 2010 that made it sound like it's still truck'n along. Apparently, it meshes up with Alan Guth's Inflationary model and the idea that there is a multiverse?

Thanks!

 

[SpeedFreek]

The idea has been cast into some doubt, so we are waiting for more data. But that doesn't stop TV programs hyping it up!

But the idea does mesh with Guth's inflationary model, in as much as the comoving world line that represents the source of the dark flow must be outside of our particle horizon but inside our past light cone. The only way this could happen (with our current understanding!) is if it was taken past (what would become) the particle horizon during the inflationary epoch.

As for the multiverse - it depends on the type of multiverse you are describing. It is only the "lowest" form - the universe outside of our particle horizon.

 

[darkmatter4brains]

thanks SF, I figured there might be some hype going on there. I was pretty sure the data set they had was not conclusive enough to be sure, but I don't beleive this show even mentioned that.

As far as inflation and darkflow, in the show I believe they were talking about the newer idea of eternal inflation, which involves an inifinity of pocket Universes, which may not even have the same laws of physics as we do. Alan Guth is a proponent of this - gets rid of the whole idea that the Universe was fine tuned for us. We're just one of many and statistics just happened to hit it just right for us in this Universe.

Here's Guth's article if you're interested:

http://arxiv.org/abs/hep-th/0702178

I don't remember exactly how they were trying to tie dark flow to this though - was eating at the same time and only hearing bits and pieces of the show.

 

[SpeedFreek]

I think they are stretching things a bit if they are linking the dark flow to a higher level of multiverse theory - infinite bubble universes. The dark flow, if it exists, is having a causal effect on our bubble, so must be in some way part of our bubble and our past light cone.

 

[ramparts]

Ugh. Science TV shows. Great for spreading awareness to interested people but take what they say with a grain of salt! Highly speculative and extremely dumbed down.

The "dark flow" is a pretty fascinating idea, and one that's still really only supported by the authors of the original paper on it. Every now and then they put out a paper with updated data claiming to find a signal for it, while most external studies have shown that their results aren't statistically significant. So I'd say it's possible but still very much in the realm of speculation.