AG Mathematische Physik, Nicolai Rothe (Technische Universität Berlin): Cosmological solutions to the semiclassical Einstein equation with Minkowski-like vacua

Nicolai Rothe (Technische
Universität Berlin)

Cosmological solutions to the semiclassical Einstein equation
with Minkowski-like vacua

Abstract:
We will discuss some newly found solutions to the full
massless semiclassical Einstein equation (SCE) in a cosmological
setting.

After a short introduction to the relevant notions we present the SCE in
a particular shape which allows for the construction of certain vacuum
states for a free, massless scalar field. These states may be viewed as
as the least possible generalization of the Minkowski vacuum to general
(cosmological) space-times. In this setting, solving the SCE breaks down
into solving a certain ODE which can be approached numerically and, at
least generically, we obtain solutions that well fit physical
expectations. Moreover, these solutions indicate dark energy as a
quantum effect back-reacting on cosmological metrics. Since in our model
m=Λ=0, this may not be traced back to the usual, obvious
dark-energy/cosmological constant effect of a quantum field. Also we
will shortly discuss some more physical problems that can be solved by
our model.