Melika Sarrami

Department of Physics, Sharif University of Technology

Non-linear Structure formation and halo statistics in the fuzzy dark matter model 

Supervisor: Shant Baghram

 Abstract: Fuzzy dark matter ( FDM ) or wave dark matter is an alternative theory designed to solve small-scale problems faced by the standard cold dark matter, such as the missing satellites problem, core cusp problem, and too big to fail problem. FDM is made up of ultra-light axions having mass ∼  that typically have de Broglie wavelength of several kpc, so in small-scales behave like a wave.

For this thesis, I aim to explore how the sub-halo structure and its features change with FDM particles masses which may be able to solve small-scale problems. We derived the halo mass function for FDM by solving the excursion set problem with a mass-dependent barrier function; then, we compared the approach and results of the ΛCDM model and halo statistics that stem from it with the FDM model. FDM model suppresses the small-scale structure of dark matter that results in a cut-off at the lower end of the halo mass function. Markovian processes have an analytical solution, but most are non markov, meaning steps are correlated. Then for this problem, we can approximate it using up-crossing in large mass structure. This approach could be intelligent because Non-Markov trajectories are more smooth than Markovian trajectories, which makes it possible to use this approximation. At the end of the project, we conduct progenitor history for FDM in different redshifts with various mass ranges using the top hat window function.

چهارشنبه  26 بهمن 1401، ساعت 10:00

Wednesday 15 February 2023 – 10:00 Tehran Time

تالار پرتوی  – دانشکده فیزیک