Seminarium Kosmologia i Fizyka Cząstek

The unification of quantum theory and gravity is one of the most crucial open problems in physics. Several approaches to a theory of quantum gravity have been developed, but in order to ultimately decide which approach describes Nature best, we need testable predictions. Finding such predictions is problematic, because quantum-gravitational effects might only become sizable at energies of the order of the Planck scale. A promising scenario to look for such effects is the highly energetic inflationary phase in the very early universe.In this talk I will give an introduction to a rather conservative approach to quantum gravity based on a canonical quantization that leads to the Wheeler-DeWitt equation. I will present how this approach has been applied to study how scalar and tensor perturbations are influenced by quantum-gravitational effects during inflation and whether the resulting corrections to the power spectra can be observed in the Cosmic Microwave Background.