Cosmology News & Events

In recent years several anomalies have been observed in decays of B-mesons. We give first a brief overview on the experimental situation. It is well know that these anomalies can be explained by adding leptoquarks or extra vector-bosons to the SM particle content.

An extended scalar sector often emerges in models motivated by the electroweak hierarchy problem. In particular, a SM triplet is interesting because its decay is very constrained at the renormalizable level. Therefore, effective operators with a low cutoff make the triplet components decay promptly.

I'll discuss the role of the Higgs boson as a probe of the hidden sector. The latter is of particular importance in cosmology as it may host dark matter and the inflaton. Due to its scalar nature, the Higgs boson provides a unique handle on properties of such Standard Model--singlet states.

Axions can play very important roles in cosmology. They are interesting candidates for dark matter, dark energy, inflation but also, in the case of the QCD axion, a natural solution to the strong CP problem. 

The reduced phase space quantization of a closed Friedmann Universe is described. Its matter content is constituted by a specific perfect fluid.  It is shown that, for this particular model, specific boundary conditions can be related to the algebra of Dirac observables.