Ciclo di seminari di cosmologia

Nei giorni 10 e 12 marzo in aula 412 si terra un ciclo di seminari/lezioni di cosmologia:

10 marzo

10:00 → 12:00 SUSY type dark matter in R^2 cosmology

We describe the cosmological evolution in the R^2 inflationary model (Starobinsky inflation). It is shown that in the post-infationary stage when the universe expansion is dominated by the oscillating curvature scalar, the particle kinetics is significantly different from the conventional Friedmann one. Thanks to that the density of heavy supersymmetric type relics, satisfying the LHC bounds could be sufficiently low to allow them to make the observed dark matter density.

Speaker: Elena Arbuzova (Dubna State University and Novosibirsk State University)

14:30 → 16:30 Present day status of primordial black holes (PBH)

During several recent years PBH became a viable and very popular candidates for darkmatter particles. Moreover, the abundance of the observed black holes in the universe in all mass intervals is found to be unexpectedly high. It is tempting to conclude that the observed BH are predominalty primordial. The pro and contra observational data are analyzed. The mass spectrum of BH is discussed.

Speaker: Alexander Dolgov (Dubna State University and Novosibirsk State University)

12 marzo

10:00 → 12:00 Problems of spontaneous and gravitational baryogenesis

Spontaneous and closely connected with it gravitational baryogenesis are very interesting examples of the baryogenesis scenarios permitting to realize successful generation of the baryon asymmetry, which violates two out of three Sakharov conditions, namely the symmetry can be generated in thermal equilibrium without explicit C/CP violation. It is argued that the traditional interpretation of the inherent (pseudo)Goldstone field as baryonic chemical potential is questionable but the magnitude of the asymmetry remains reasonably large. On the other hand, it is argued that gravitational baryogenesis leads to strongly unstable cosmology and is excluded in the original scenario.

Speaker: Elena Arbuzova (Dubna State University and Novosibirsk State University)

14:30 → 16:30 Striking physical phenomena around Black Holes0

Several examples of unusual physical effects around black holes,
discussed in several publications mostly many years ago but which are mostly not widely known, are discussed. Among them are: superluminous propagation of light, proton-to-positron transformation, possible non-conservation of electric charge and cosmological electric asymmetry and some more.

Speaker: Alexander Dolgov (Dubna State University and Novosibirsk State University)