Dark energy might not be spread out evenly; it could be bunching up into giant, invisible clouds.
arXiv · March 18, 2026 · 2603.16248
The Takeaway
We usually think of dark energy as a uniform force that's spread perfectly thin across the universe. This study shows it can actually 'clump' together inside galaxies, creating invisible structures that could make up 10% of a galaxy's mass and throw off our current measurements of the cosmos.
From the abstract
We present the first cosmological simulations that consistently include nonlinear clustering dark energy evolved as a fluid with the numerical hydrodynamics code Nefertiti. Dark energy perturbations become fully nonlinear on small scales, developing significant density fluctuations without exhibiting the catastrophic instabilities previously reported. We show results for the density distribution, power spectrum, and halo profiles of dark energy. Clustering dark energy contributes to the total de