| Primordial inflation is a conjectured epoch of accelerated expansion during the very early universe. Quantum effects, which are too small to be seen under normal circumstances, can be so vastly enhanced during inflation that they leave an observable imprint on the current universe. For example, it is believed that the simplest kind of quantum fluctuations from near the end of inflation provided the tiny inhomogeneities, which grew over 14 billion years of gravitational collapse, to become the galaxies and galactic clusters we see today. Little is known about what can result from more complicated quantum effects. I propose to make a systematic study of this, working with Professor Tomislav Prokopec at the University of Utrecht. Work in this subject involves a specialized technique of quantum field theory known as the Schwinger-Keldysh formalism. It also typically involves a technique developed by cosmologist Alexei Starobinsky for adding up the most important contributions from quantum effects that grow with time. My graduate research uncovered such an effect on the way gravitational waves modify ordinary matter. I also generalized Starobinsky?s technique to the particles that are responsible for producing mass. Many of the other results in this subject have been discovered by Professor Prokopec and his collaborators. This topic has great potential importance for cosmology and also for fundamental theory. Much of our current understanding of cosmology is based upon ignoring the possibility of significant quantum effects. To explain observed phenomena one must then resort to a number of questionable assumptions about the initial state of the universe and about its composition. It may be that important quantum effects can explain things without dubious assumptions. It might even be that the explanation requires the laws of physics to take a certain form, which would point to fundamental theory. |
