Testing the self-consistency of the excursion set approach to predicting the dark matter halo mass function

Area of Science:

• Cosmology
• Astrophysics
• Statistical Mechanics

Background:

• The excursion set approach is a theoretical framework for predicting dark matter halo abundance.
• A critical overdensity threshold (barrier) is essential for this formalism.
• The physical meaning of this barrier is unclear due to averaging over initial field positions.

Purpose of the Study:

• To investigate the physical motivation and meaning of the barrier in the excursion set approach.
• To develop a self-consistent model for halo abundance predictions.

Main Methods:

• Analyzing the statistical assumptions underlying the excursion set approach.
• Implementing a drifting diffusing barrier model.

Main Results:

• The drifting diffusing barrier model provides a self-consistent description of halo abundance.
• This model accurately describes the initial overdensities of protohalo patches.

Conclusions:

• The drifting diffusing barrier model offers a physically motivated and consistent description within the excursion set framework.
• This approach enhances the predictive power of dark matter halo formation models.