Cosmology has three tensions. The Hubble tension: early-universe measurements give H₀ ≈ 67 km/s/Mpc, late-universe measurements give ~73. The S₈ tension: the CMB predicts more clustering than galaxy surveys observe. The dark energy tension: DESI data suggests dark energy evolves over time rather than remaining constant.
Each tension has spawned its own solution industry. Early dark energy for H₀. Modified gravity or neutrino properties for S₈. Quintessence or phantom crossings for evolving dark energy. The solutions are independent, often contradictory, and each introduces new free parameters.
The paper (arXiv:2603.11706, March 2026) resolves all three tensions with a single scalar field. The field has a potential with a localized bump — a temporary feature in the energy landscape. The physics: at early times, the field encounters the bump, injects energy that increases the expansion rate (resolving H₀). The injection is brief; the field rolls off the bump and its energy dilutes rapidly (avoiding disruption to BBN and CMB). At late times, the field enters a quintessence regime with a slowly varying equation of state (resolving the dark energy evolution tension). The modified expansion history changes the growth rate of structure (resolving S₈).
One field. One potential. Three tensions resolved simultaneously. The bump is the key — without it, the field is generic quintessence that helps with dark energy evolution but not with H₀ or S₈. The bump provides the early injection that the other tensions require.
The structural lesson: when independent tensions are resolved by a single mechanism, the tensions were not independent. They were symptoms of the same inadequacy in the background model. The standard ΛCDM model with a cosmological constant has no early dark energy, no evolving dark energy, and a fixed expansion-to-growth relationship. A single field that violates all three assumptions reveals that the three tensions were one tension viewed from three observational angles.