At the moment of the Big Bang there was almost the same amount of matter and antimatter. However due to a small preference for normal matter (cp violation) a small percentage of residual matter was left over with the bulk of the initial material being annihilated and converted into gamma rays which cooled (universal expansion/cooling) to the microwave 4K background seen by radio astronomers. This is fairly well understood I believe. But at the moment that the universe contained equal matter and antimatter in whatever exotic form (still too hot for normal hadrons like neutrons and protons I suspect) this primordial bulk of mass (up to 2 billion times the current universe's mass) should have generated an enormous gravitation field/wave which should still be traveling throughout the universe. Is this a realistic idea? And if so, wouldn't this primordial gravity be uniform similar to the background radiation (and equally as diluted). Also, I would think this extra "universal gravity field" would cause a significant discrepancy in the expansion of the universe? In the early universe (the further you look back in time/distance) the stronger the gravity field would be and it's effect much greater it's influence on the structure and development of the universe. Bottom line: Is there a Big Bang Background Gravitational Field?