Reuven Opher, Univ. of Sao Paulo

Magnetic Fields and Dark Matter, Two of the Most Important parameters in Understanding Astrophysical Phenomena

Magnetic fields and dark matter are responsible for some of the most important phenomena in astrophysics. Magnetic fields are primarily responsible for the formation of stars like the sun, allowing for the loss of intrinsic angular momentum of accreting gas to form stars. They also play crucial roles in galaxies, such as the creation and confinement of Megaparsec jets, acceleration of cosmic rays and accretion onto central massive black holes. Dark matter halos create gravitational wells allowing for baryons to form galaxies in the relatively short time of the age of the universe. In this talk I will discuss some of the important effects of magnetic fields and dark matter,in particular, some of our recent studies in these areas. We showed recently that magnetic fields can be created by thermal fluctuations in the early universe and that these primordial magnetic fields can prevent the formation of small mass galaxies, in agreement with observations. We also showed that an explosion of a single supernova can drastically change the density profile of a small-mass dark matter halo, changing the infinite predicted central density of the dark matter halo to a finite density, as observed. We also showed recently that a small oscillation in the commonly used smooth inflaton potential in the primordial universe can decrease drastically the predicted number of small-mass dark matter halos. This could explain why the thousands of small dark matter halos, predicted by the commonly used smooth primordial inflaton potential, are not observed.

Host:  Richard Lovelace