Our whole universe might just be one branch of a giant 'reality tree' that we can actually spot using space ripples.
March 20, 2026
Original Paper
Branching Universes
arXiv · 2603.18147
The Takeaway
Researchers propose a framework where our universe is one of several possible 'branches' existing simultaneously. They identified a specific distortion in gravitational waves that would act as a fingerprint, potentially allowing us to observe the physical influence of these other branches for the first time.
From the abstract
We propose the idea that our Universe is a realization among different possible branches, which can be observationally tested through the modified dispersion relation of the gravitational waves. We achieve this through a framework of spatially constrained vector fields. We show that the simplest realizations of such theories in flat and cosmological spacetimes do not introduce new propagating modes, but they give rise to tensor perturbations that differ from those of standard general relativity.