Speakers
Description
Chair: Robin Diedrichs
Co-Chair: Saeed Rastgoo
Mentors: Jürgen Schaffner-Bielich, Nassim Bozorgnia, Sean Tulin
Junior mentors: Daniel Schmitt, Edwin Genoud-Prachex
Dark matter structures are known to span from dwarf
galaxies to the large scale structure of the cosmic web.
But there is an uncharted territory: Do dark matter structures exist on (much) smaller scales?
The research goals are divided in
• Study of dark star properties
• Derive observational constraints on dark stars from tidal streams
Dark stars properties are investigated along these lines:
• What are the properties of dark matter stars?
• Solve the Tolman-Oppenheimer-Volkoff
equations and derive mass-radius relations
• Calculate the I-Love-Q relations of dark stars
and compare to the one of neutron stars
Dark stars passing through the stream cause dynamical heating.
The gravitational encounters impart random kicks to stream stars.
A limit on dark stars using observed velocity dispersion of GD-1 stream can be derived.
The constraint is not just for dark stars, but for any compact
dark object as primordial black holes and MACHOs (Massive Compact Halo Objects).
The goal is to derive (and publish) new general exclusion limit.
Phase 1: Analytic calculation
• Compute dynamical heating of streams from compact objects
• Point-like objects (black holes), finite objects (dark stars)
→Use mass-radius relation
Phase 2: Numerical simulation
• Simulation of tidal stream + encounters from compact objects
• Goal: numerical validation of analytic results
Phase 3: Data analysis
• Explore Gaia data for calculating GD-1 stream velocity
dispersion (reproducing known results)
