Cosmology Seminar: Susmita Adhikari and Arka Banerjee (University of Illinois)

Date: 
11:00am to 12:00pm
Monday March 6th, 2017

Susmita:

Splashback and outskirts of Dark Matter halos

Recent work has shown that density profiles in the outskirts of dark matter halos can become extremely steep over a narrow range of radius, deviating from well-known fitting functions like the Navarro-Frenk-White(NFW) profile. This behavior is produced by splashback material on its first apocentric passage after accretion. The location of this splashback feature may be understood quite simply, from first principles. I will discuss how this feature may be used as a probe of fundamental physical phenomena like dynamical friction and also of exotic physics. I will also review the progress in the detection of this feature in observations of galaxy clusters.

Arka:

Simulating nonlinear cosmological structure formation with massive neutrinos

Accurate measurements of neutrino mass eigenstates could offer a window into physics beyond the Standard Model of particle physics. Apart from oscillation experiments, cosmological probes offer a promising avenue for neutrino mass measurements. One such probe is the effect of massive neutrinos on cosmological structure formation. In this talk, I will first discuss a technique which can simulate cosmologies with massive neutrinos accurately down to scales where the clustering of neutrinos is fully nonlinear, while not suffering from shot noise effects that are seen in standard N-body simulations. I will then talk about a specific observable signature that massive neutrinos produce on Large Scale Structure - a strong scale dependent bias of voids even on large scales.

Location: 
Campus, Varian 355