## Graduate Seminar, 15th April

**Speaker**: Artur Miroszewski

**Title**: Early universe cosmology and the coherent states

**Abstract**: The
theory of General Relativity seems to be a well chosen tool to describe
the evolution of the universe. Starting from very simplified model of
the universe, Friedmann-Lemaître-Robertson-Walker spacetime, we are
able to explain most of the observable phenomena on the cosmic scale.
On the other hand the cosmological solutions in GR tend to contain
past-incomplete geodesics, also know as singularities. The
singularities occur in the very early universe regimes, where apart
from the GR we should take into account quantum effects. Although the
theory of Quantum Gravity seems to be far from invented and understood,
the semi-classical approach may be able to point us to some features
of it. During my talk I will present the semi-classical approach based
on the coherent states, leading to the Big Bang singularity avoidance
scenario- the Big Bounce.