Who: Sergey Sibiryakov (CERN)
When: Tuesday, March 21, 2017 at 14:15
Where: The CP³ meeting room
There is compelling observational evidence for existence of dark matter — a substance of unknown nature that interacts gravitationally with ordinary matter and participates, or even dominates, in the formation of galaxies and other cosmic structures. Despite many candidate theoretical models and a vast experimental effort to test them, dark matter has remained elusive up to now.
On the other hand, radio pulsars are rapidly rotating neutron stars emitting a beam of electromagnetic radiation which points towards the Earth for a fraction of the rotation period. There exists a large category of pulsars whose periods are known to be extremely stable, so they can be considered as precise clocks positioned at astronomical distances from the Earth. Timing the signals coming from them brings a wealth of information about their dynamics and environment.
In this lecture I will focus on the hypothesis that dark matter is represented by an ultra light scalar field performing coherent oscillations. I will review the theoretical motivation and existing constraints on this hypothesis. Then I will discuss how it can be further tested using pulsar timing.