An excursion set model of hierarchical clustering: ellipsoidal collapse and the moving barrier

Sheth, Ravi K.; Tormen, Giuseppe

doi:10.1046/j.1365-8711.2002.04950.x

Cited by 934 publications

(1,274 citation statements)

References 43 publications

(115 reference statements)

Supporting

Mentioning

1,213

Contrasting

Order By: Relevance

“…We studied dependence of the mass function on Λ, in addition to ellipsoidal collapse [42]. Without significantly changing P 1 (F ),we find that the delayed structure formation gives a roughly three times larger total flux (by increasing the number of halos N ) than if we had used a mass function for which the cosmological constant is ignored [43,44].…”

Section: Subleading Effectsmentioning

confidence: 94%

Modelling the flux distribution function of the extragalactic gamma-ray background from dark matter annihilation

Feyereisen

Ando

Lee

2015

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

Abstract. The one-point function (i.e., the isotropic flux distribution) is a complementary method to (anisotropic) two-point correlations in searches for a gamma-ray dark matter annihilation signature. Using analytical models of structure formation and dark matter halo properties, we compute the gamma-ray flux distribution due to annihilations in extragalactic dark matter halos, as it would be observed by the Fermi Large Area Telescope. Combining the central limit theorem and Monte Carlo sampling, we show that the flux distribution takes the form of a narrow Gaussian of 'diffuse' light, with an 'unresolved point source' power-law tail as a result of bright halos. We argue that this background due to dark matter constitutes an irreducible and significant background component for point-source annihilation searches with galaxy clusters and dwarf spheroidal galaxies, modifying the predicted signal-to-noise ratio. A study of astrophysical backgrounds to this signal reveals that the shape of the total gamma-ray flux distribution is very sensitive to the contribution of a dark matter component, allowing us to forecast promising one-point upper limits on the annihilation cross section. We show that by using the flux distribution at only one energy bin, one can probe the canonical cross section required for explaining the relic density, for dark matter of masses around tens of GeV.

show abstract

Section: Subleading Effectsmentioning

confidence: 94%

Modelling the flux distribution function of the extragalactic gamma-ray background from dark matter annihilation

Feyereisen

Ando

Lee

2015

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

show abstract

“…First of all, as argued by Bond & Myers (1996), the gross features of a halo are sensitive to only a few dynamical variables of the progenitor, such as the bulk velocity, tidal tensor, and average overdensity. The model then proposed is the homogenous ellipsoidal collapse (HEC) model, which provides much more information than SC, and has been incorporated in many frameworks like the peak-patch approach (Bond & Myers 1996) and the excursion set model (Sheth & Tormen 2002). Therefore, to a certain extent, we could the approximate internal dynamics with just the density and shape.…”

Section: Introductionmentioning

confidence: 99%

Statistical Decoupling of a Lagrangian Fluid Parcel in Newtonian Cosmology

Wang

Szalay

2016

ApJ

View full text Add to dashboard Cite

The Lagrangian dynamics of a single fluid element within a self-gravitational matter field is intrinsically non-local due to the presence of the tidal force. This complicates the theoretical investigation of the nonlinear evolution of various cosmic objects, e.g., dark matter halos, in the context of Lagrangian fluid dynamics, since fluid parcels with given initial density and shape may evolve differently depending on their environments. In this paper, we provide a statistical solution that could decouple this environmental dependence. After deriving the evolution equation for the probability distribution of the matter field, our method produces a set of closed ordinary differential equations whose solution is uniquely determined by the initial condition of the fluid element. Mathematically, it corresponds to the projected characteristic curve of the transport equation of the density-weighted probability density function (ρPDF). Consequently it is guaranteed that the one-point ρPDF would be preserved by evolving these local, yet nonlinear, curves with the same set of initial data as the real system. Physically, these trajectories describe the mean evolution averaged over all environments by substituting the tidal tensor with its conditional average. For Gaussian distributed dynamical variables, this mean tidal tensor is simply proportional to the velocity shear tensor, and the dynamical system would recover the prediction of the Zel'dovich approximation (ZA) with the further assumption of the linearized continuity equation. For a weakly non-Gaussian field, the averaged tidal tensor could be expanded perturbatively as a function of all relevant dynamical variables whose coefficients are determined by the statistics of the field.

show abstract

“…Utilizing the measured backsplashless mass functions and conditional mass functions from the MDPL simulation, and the SO algorithm halo mass error model of §2.4, we constrain the parameters of the Sheth & Tormen (2002) mass function and the PCH merger tree algorithm.…”

Section: Resultsmentioning

confidence: 99%

“…To model the resulting backsplashless mass function we use the parametric form proposed by Sheth & Tormen (2002),…”

Section: Halo Mass Functionsmentioning

confidence: 99%

The mass function of unprocessed dark matter haloes and merger tree branching rates

Benson

2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

A common approach in semi-analytic modeling of galaxy formation is to construct Monte Carlo realizations of merger histories of dark matter halos whose masses are sampled from a halo mass function. Both the mass function itself, and the merger rates used to construct merging histories are calibrated to N-body simulations. Typically, "backsplash" halos (those which were once subhalos within a larger halo, but which have since moved outside of the halo) are counted in both the halo mass function, and in the merger rates (or, equivalently, progenitor mass functions). This leads to a double-counting of mass in Monte Carlo merger histories which will bias results relative to N-body results. We measure halo mass functions and merger rates with this double-counting removed in a large, cosmological N-body simulation with cosmological parameters consistent with current constraints. Furthermore, we account for the inherently noisy nature of N-body halo mass estimates when fitting functions to N-body data, and show that ignoring these errors leads to a significant systematic bias given the precision statistics available from state-of-the-art N-body cosmological simulations.

show abstract

An excursion set model of hierarchical clustering: ellipsoidal collapse and the moving barrier

Cited by 934 publications

References 43 publications

Modelling the flux distribution function of the extragalactic gamma-ray background from dark matter annihilation

Modelling the flux distribution function of the extragalactic gamma-ray background from dark matter annihilation

Statistical Decoupling of a Lagrangian Fluid Parcel in Newtonian Cosmology

The mass function of unprocessed dark matter haloes and merger tree branching rates

Contact Info

Product

Resources

About