Does the universe need exotic matter, or is standard cosmology wrong?

Energy conditions—rules that forbid negative energy and repulsive gravity—are fundamental to general relativity but violated by standard ΛCDM during inflation and dark energy. Using measurements of ancient galaxies and stellar ages, researchers compared ΛCDM to an alternative model (Rh=ct universe) and found the alternative fits 92% better and satisfies all energy constraints, while ΛCDM violates them at low redshifts.