Can dark energy switch signs to fix neutrino mass tensions?

Recent measurements suggest neutrino masses incompatible with oscillation experiments—a physical impossibility. The team tested whether tweaking dark energy models could reconcile the data by altering cosmic expansion at early times while preserving late-time measurements. A "sign-switching" dark energy model that turns negative above redshift 2.4 recovers physically sensible positive neutrino masses, though it's not the statistically favored explanation.