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Universal properties of dark matter halos
A Boyarsky1, A Neronov, O Ruchayskiy
1Ecole Polytechnique Fédérale de Lausanne, FSB/ITP/LPPC, BSP 720, CH-1015, Lausanne, Switzerland.
Physical Review Letters
|September 28, 2010
Summary
The universal density-size relation in dark matter halos holds across cosmic scales. Analytical models explain this property within the standard Lambda Cold Dark Matter (ΛCDM) model, aiding in testing gravity theories.
Area of Science:
- Cosmology
- Astrophysics
- Galaxy Formation
Background:
- Observed dark matter halos exhibit a universal relation between density and size.
- This relation spans a vast range of scales, from dwarf galaxies to galaxy clusters.
- Previous studies confirmed this empirical relation.
Purpose of the Study:
- To explain the origin of the universal density-size relation in dark matter halos.
- To test the consistency of this relation with the Lambda Cold Dark Matter (ΛCDM) model.
- To develop a framework for constraining alternative gravity theories and ΛCDM deviations.
Main Methods:
- Analytical investigation using the secondary infall model.
- Comparison of theoretical predictions with observational data and N-body simulations.
- Developing a qualitative understanding of halo formation and evolution.
Main Results:
- The secondary infall model analytically explains the universal density-size relation in ΛCDM.
- The ΛCDM N-body simulations are consistent with this observed universal relation.
- The model provides a basis for predicting how deviations from ΛCDM affect this relation.
Conclusions:
- The universal density-size relation is a robust prediction of the ΛCDM model.
- The secondary infall model offers valuable insights into dark matter halo structure.
- This work provides a new observational avenue to constrain modified gravity theories and test the ΛCDM paradigm.
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