Dear All,
Virgile Dandoy (new postdoc in the service de Physique Théorique) kindly agreed to present his past and ongoing works during a seminar which will take place next Friday, the
8th of December, at 11am, in room 2.N7.110 (building NO, campus Plaine). More precisely, he will tell us about
Clumpy Dark Matter Phenomenology: A Study of Axion Miniclusters and Primordial Black Holes
We investigate the possibility of dark matter forming small scale gravitationally bound structures. One notable illustration is given by the axion miniclusters. Emerging within a scenario where axions are produced after inflation, these structures consist
of axions bound by gravitational forces, with a mass close to the one of the Moon with the radius of the Sun. Given that they would form as early as during the matter-radiation equality epoch, the initial population of axion miniclusters is subjects to many
effects that alter, damage and even destroy them. We study how those structures would survive once they become bound in the galaxy and start interacting with stars. Finally, we show the typical signal in experiment we should expect once one of them encounter
the Earth. We also study the new potential signal of gravitational waves from PTAs. In particular, we show that the formation of primordial black holes and the existing constrains on their abundance are seriously constraining some early universe scenarios.
Best regards,
Gaétan