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harshika1324Analyzing the Role of Dark Matter in Early Galaxy Formation: A Simulation
Study ✨
Introduction: Problem & Context
Current cosmological models, such as the 3$\Lambda$CDM model, posit that Dark Matter
(DM) constitutes approximately 85% of the total matter in the universe, providing the
gravitational scaffolding necessary for structure formation.4 However, the precise dynamics and
distribution of DM halos during the epoch of reionization (when the first stars and galaxies
formed, approximately 150 million to 1 billion years after the Big Bang) remain poorly
understood. A particular challenge is reconciling the predicted abundance of small DM subhalos
with the observed scarcity of ultra-faint dwarf galaxies. This research aims to use high-resolution
simulations to track the merger history and baryonic interactions within DM halos in the early
universe.
Proposed Methodology & Approach
The study will rely on a new suite of high-resolution N-body and hydrodynamic cosmological
simulations (e.g., using the AREPO or GADGET codes) calibrated to reproduce key
observational constraints, such as the Cosmic Microwave Background (CMB) and the luminosity
function of high-redshift galaxies. The methodology will focus on isolating and analyzing the
tidal stripping and baryonic feedback mechanisms (e.g., supernova explosions, radiation
pressure) within DM halos corresponding to nascent galaxies ($z > 6$). By varying the particle
physics properties of DM (e.g., warm vs. cold DM), we can test different DM models against the
emergent properties of the simulated galactic structures.
Expected Conclusion & Significance
The research is expected to clarify the extent to which baryonic processes can "quench" star
formation in low-mass DM halos, offering a possible resolution to the "missing satellites
problem." If the simulations robustly demonstrate that feedback mechanisms preferentially expel
gas from smaller halos, it would strengthen the case for the standard Cold Dark Matter (CDM)
paradigm. The findings will provide crucial constraints for next-generation observatories like the
James Webb Space Telescope (JWST) and aid in the theoretical interpretation of their data
regarding the universe's oldest structures.