Even if the universe were perfectly empty and flat, quantum weirdness would force it to start expanding on its own.
April 2, 2026
Original Paper
The Semiclassical Einstein-Klein-Gordon System: Asymptotic Analysis of Minkowski Spacetime
arXiv · 2604.01047
The Takeaway
Researchers discovered that Minkowski space—the standard physics model for a static, empty vacuum—is inherently unstable when quantum matter is included. Their math shows that instead of staying still, space will naturally grow at an exponential rate, suggesting that the 'dark energy' expansion of our own universe might be a fundamental byproduct of quantum backreactions.
From the abstract
We establish the linear instability of the semiclassical Einstein-Klein-Gordon system linearised about the Minkowski vacuum spacetime. The proof relies on formulating a forcing problem for both metric and state perturbations within the space of past-compact sections. This geometric framework admits a unique tensor decomposition which, in conjunction with the quantum Møller operator, enables the decoupling of the linearised system into two distinct Cauchy problems. Consequently, the metric pertur