Testing the self-consistency of the excursion set approach to predicting the dark matter halo mass function.
The excursion set approach provides a framework for predicting how the abundance of dark matter halos depends on the initial conditions. A key ingredient of this formalism is the specification of a critical overdensity threshold (barrier) which protohalos must exceed if they are to form virialized halos at a later time. However, to make its predictions, the excursion set approach explicitly averages over all positions in the initial field, rather than the special ones around which halos form, so it is not clear that the barrier has physical motivation or meaning. In this Letter we show that once the statistical assumptions which underlie the excursion set approach are considered a drifting diffusing barrier model does provide a good self-consistent description both of halo abundance as well as of the initial overdensities of the protohalo patches.
Ludwig-Maximilians-Universitat München, Universitäts-Sternwarte München, Scheinerstrasse 1, D-81679 München, Germany and Excellence Cluster Universe, Boltzmannstrasse 2, D-85748 Garching bei München, Germany and Laboratoire Univers et Théories (LUTh), UMR 8102 CNRS, Observatoire de Paris, Université Paris Diderot, 5 Place Jules Janssen, 92190 Meudon, France.
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Achitouv
Laboratoire Univers et Théories (LUTh), UMR 8102 CNRS, Observatoire de Paris, Université Paris Diderot, 5 Place Jules Janssen, 92190 Meudon, France.
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Rasera
The Abdus Salam International Center for Theoretical Physics, Strada Costiera, 11, Trieste 34151, Italy and Center for Particle Cosmology, University of Pennsylvania, 209 S. 33rd Street, Philadelphia, Pennsylvania 19104, USA.
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Sheth
Laboratoire Univers et Théories (LUTh), UMR 8102 CNRS, Observatoire de Paris, Université Paris Diderot, 5 Place Jules Janssen, 92190 Meudon, France.
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Corasaniti