Scientists exploring an overlooked branch of an alternative gravity theory have found that dark energy, the mysterious force driving the Universe's accelerating expansion, may have flipped from negative to positive roughly 9.5 billion years ago. The theoretical work suggests the force could have undergone a dramatic reversal, shifting from a state that decelerated cosmic expansion to one that drives it outward. If confirmed, the finding would reshape prevailing models of cosmic history, which generally treat dark energy as a constant or smoothly evolving component. The researchers emphasize that the result emerges from a specific, previously neglected regime of the theory and requires further scrutiny.
The proposed reversal would carry significant implications for cosmology, potentially offering new insight into longstanding tensions in measurements of the Universe's expansion rate. A sign change in dark energy would alter predictions for the growth of cosmic structures and the distant Universe's behavior, providing testable signatures for upcoming astronomical surveys. Independent experts caution that alternative gravity frameworks remain highly speculative and that observational evidence for such a transition has yet to be established. The team's findings add to growing interest in whether dark energy is truly constant or has evolved over cosmic time, a question central to modern physics.
Independent reporting synthesized from primary wires and global correspondents.