A new model suggests the unevenness of Cosmic Microwave Background (CMB) in the universe may be caused by an imprint left over from before the beginning of the universe. Some scientists believe that if the model holds up, we may have a chance to learn more about what happened before the Big Bang.
Scientists think the normal variations in temperature and density predicted by inflation became the seeds for the structure we see today throughout the universe. Soon after inflation, the denser areas would have attracted more matter and eventually grown into the clusters and galaxies we see today, while less dense regions would have become voids mostly absent of galaxies, stars and planets.
But the normal model of inflation can't account for the asymmetry now noted. To try to explain that, Carroll, astrophysicist Marc Kamionkowski and graduate student Adrienne Erickcek (all at Caltech) tested a new version of inflation theory, in which two fields are responsible for the universe's early bloom of expansion..