Wednesday, August 19, 2015

Physics Q&A #2: The Inflaton

I spend a lot of time on this blog explaining a physical spacetime model and the underlying metaphysics. In this series of posts, each entry poses a physics question for the spacetime model, along with the answer. A separate series of posts answers metaphysics questions.

Physics Question #2. What is the inflaton (the field responsible for cosmic inflation)? In my spacetime model, spacetime is self-generating. Spacetime itself is the inflaton. Points are defined recursively, with the result that the number of points increases from N to 2N at each discrete time step. This is an extremely rapid expansion. It never stops, so spacetime is always inflating.

Initially, there is no matter and there are only a few points having random position quantum numbers. As time goes on, the proliferation of points, together with their gravitational attraction (see question #1), causes the distance between points to decrease. Fermionic points must avoid each other, so they have some mean free path, which is the average distance a fermionic point can travel in any direction without encountering another fermionic point. The inverse of this mean free path is a scalar field that plays the role of the inflaton in triggering a phase transition in which all matter is created. The potential of the inflaton field has a minimum where the force of gravity acting on the fermionic points equals the degeneracy pressure that keeps them apart. When the inflaton reaches this minimum, the result is coherent oscillations of the mean free path parameter throughout spacetime. These oscillations decay into matter particles and radiation by raising some points above their ground state energy. Points where there are matter particles are decoupled from spacetime as a whole. The very rapid inflation of the universe stops at the phase transition, but spacetime as a whole continues to inflate at a much slower but still accelerating rate. This effect is attributed to dark energy or a cosmologicl constant, but it is simply the continued production of fermionic spacetime points at a much slower rate. For the subset of spacetime that contains matter, this acceleration has little effect at first, but becomes more significant as time goes on.

Most inflationary models predict that galactic distance scales were smaller than the Planck length before inflation. This is a problem, since spacetime is believed to be structureless at sub-Planckian scales. In my spacetime model, all scales start out larger than the Planck length and stay that way. The minimum distance, that is, the Planck length, is established only at the end of inflation. Two other problems of conventional inflation models are: 1) they have difficulty producing primordial density perturbations that are as small in amplitude as those observed in the cosmic microwave background radiation (CMBR), which are at the 10-5 level, and 2) they predict more large-angle power in the CMBR than is observed. The inflaton spacetime model may be free of these problems. The end of inflation in the inflaton spacetime model is more of a crash than a smooth transition to the minimum of the inflaton potential. This may produce density perturbations that are both smaller in amplitude and shorter in wavelength.