We propose that the initial state of the Universe was an isotropic state of maximal entropy. Such a state can be described in terms of closed, interacting, fundamental strings in their hightemperature Hagedorn phase and cannot be described by a semiclassical spacetime geometry. If one nevertheless insists on an effective semiclassical description by ignoring the entropy, this leads to a partially equivalent description in which the pressure appears to be negative and equal in magnitude to the energy density, as if the energymomentum tensor was that of a cosmological constant. From this effective perspective, the state describes a period of stringscale inflation. The stringy microscopic description determines the parameters of the model of inflation, as well as the cosmological observables, in terms of the string length scale and coupling strength.
Wednesday
3 Jul/19
11:30

13:30
(Europe/Zurich)
A maximalentropy initial state of the Universe as a microscopic description of inflation in terms of fundamental strings
Where:
4/2011 at CERN