I like to imagine the Universe with the effects attributed to inflation and dark energy actually being explained by inverse curvature from antimatter (think relic antineutrinos). Every particle (including photons) would follow the curvature of spacetime, but antimatter would cause inverse curvature, and photons (perhaps bosons in general) would be passive rather than acting on it (inertial "mass" / momentum only).
This flies in the face of the Equivalence Principle, and requires that light's wavelength shifts due to the relative time where its energy is measured--not because of an equal and opposite gravitational interaction with the masses causing the gravitation.
Perhaps the most nonsensical consequence is the behavior of a particle-antiparticle pair co-accelerating to infinity...unless their eventual merger through relativity (length contraction) and quantum mechanics (tunneling into a merged state) actually explains the mechanism for annihilation.
The only testable prediction I have: Distant galaxies will be "too mature" for their apparant distance in space and time, meaning that the light has aged more than the distances would suggest (time slows in the presence of a gravity well, and would do the opposite for regions of space with inverse curvature--see above, re:inflation and the very start of the Universe).
This flies in the face of the Equivalence Principle, and requires that light's wavelength shifts due to the relative time where its energy is measured--not because of an equal and opposite gravitational interaction with the masses causing the gravitation.
Perhaps the most nonsensical consequence is the behavior of a particle-antiparticle pair co-accelerating to infinity...unless their eventual merger through relativity (length contraction) and quantum mechanics (tunneling into a merged state) actually explains the mechanism for annihilation.
The only testable prediction I have: Distant galaxies will be "too mature" for their apparant distance in space and time, meaning that the light has aged more than the distances would suggest (time slows in the presence of a gravity well, and would do the opposite for regions of space with inverse curvature--see above, re:inflation and the very start of the Universe).