The presence of the extra-universal matter suggests that our universe is part of something bigger – a multiverse – and that whatever is out there is very different from the universe we know, according to study leader Alexander Kashlinsky, an astrophysicist at NASA’s Goddard Space Flight Center in Maryland.

The theory could rewrite the laws of physics. Current models say the known, or visible, universe – which extends as far as light could have traveled since the big bang – is essentially the same as the rest of space-time (the three dimensions of space plus time).
…
Not everyone is ready to rewrite physics just yet. Astrophysicist Hume Feldman of the University of Kansas has detected a similar, but weaker, flow. He said the Kashlinsky team’s study is “very interesting, very intriguing, [but] a lot more work needs to be done.

“It’s suggestive that something’s going on, but what exactly is going on? It basically tells us to investigate,” he said. David Spergel, an astrophysicist at Princeton University, echoed the sentiment. “Until these results are reanalyzed by another group, I have strong doubts about the validity of the conclusions of this paper,” he wrote in an email.