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相关论文: Halo abundances and counts-in-cells: The excursion…

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We provide a simple formula that accurately approximates the first crossing distribution of barriers having a wide variety of shapes, by random walks with a wide range of correlations between steps. Special cases of it are useful for…

宇宙学与河外天体物理 · 物理学 2013-01-25 Marcello Musso , Ravi K. Sheth

We exploit the excursion set approach in integral formulation to derive novel, accurate analytic approximations of the unconditional and conditional first crossing distributions, for random walks with uncorrelated steps and general shapes…

宇宙学与河外天体物理 · 物理学 2015-06-16 A. Lapi , P. Salucci , L. Danese

Recently, we provided a simple but accurate formula which closely approximates the first crossing distribution associated with random walks having correlated steps. The approximation is accurate for the wide range of barrier shapes of…

宇宙学与河外天体物理 · 物理学 2014-07-09 Marcello Musso , Ravi K. Sheth

In the Excursion Set approach, halo abundances and clustering are closely related. This relation is exploited in many modern methods which seek to constrain cosmological parameters on the basis of the observed spatial distribution of…

宇宙学与河外天体物理 · 物理学 2012-02-23 Aseem Paranjape , Ravi K. Sheth

We study the effects of primordial non-Gaussianity on the large scale structure in the excursion set approach, accounting for correlations between steps of the random walks in the smoothed initial density field. These correlations are…

宇宙学与河外天体物理 · 物理学 2012-02-23 Marcello Musso , Aseem Paranjape

We describe a simple fully analytic model of the excursion set approach associated with two Gaussian random walks: the first walk represents the initial overdensity around a protohalo, and the second is a crude way of allowing for other…

宇宙学与河外天体物理 · 物理学 2015-06-12 Emanuele Castorina , Ravi K. Sheth

We describe a model of dark matter halo abundances and clustering which combines the two most widely used approaches to this problem: that based on peaks and the other based on excursion sets. Our approach can be thought of as addressing…

宇宙学与河外天体物理 · 物理学 2015-06-05 Aseem Paranjape , Ravi K. Sheth

We present a new method to compute the first crossing distribution in excursion set theory for the case of correlated random walks. We use a combination of the path integral formalism of Maggiore & Riotto, and the integral equation solution…

宇宙学与河外天体物理 · 物理学 2014-02-18 Arya Farahi , Andrew J. Benson

The simplest stochastic halo formation models assume that the traceless part of the shear field acts to increase the initial overdensity (or decrease the underdensity) that a protohalo (or protovoid) must have if it is to form by the…

宇宙学与河外天体物理 · 物理学 2014-07-09 Marcello Musso , Ravi K. Sheth

A classic method for computing the mass function of dark matter halos is provided by excursion set theory, where density perturbations evolve stochastically with the smoothing scale, and the problem of computing the probability of halo…

宇宙学与河外天体物理 · 物理学 2011-02-11 Michele Maggiore , Antonio Riotto

We describe how to extend the excursion set peaks framework so that its predictions of dark halo abundances and clustering can be compared directly with simulations. These extensions include: a halo mass definition which uses the TopHat…

宇宙学与河外天体物理 · 物理学 2015-06-11 Aseem Paranjape , Ravi K. Sheth , Vincent Desjacques

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 comes from the physics of halo formation: the specification of a…

宇宙学与河外天体物理 · 物理学 2014-11-12 I. Achitouv , Y. Rasera , R. K. Sheth , P. S. Corasaniti

The excursion set approach allows one to estimate the abundance and spatial distribution of virialized dark matter haloes efficiently and accurately. The predictions of this approach depend on how the nonlinear processes of collapse and…

天体物理学 · 物理学 2009-11-06 Ravi K. Sheth , Giuseppe Tormen

We use the Excursion Set formalism to compute the properties of the halo mass distribution for a stochastic barrier model which encapsulates the main features of the ellipsoidal collapse of dark matter halos. Non-markovian corrections due…

宇宙学与河外天体物理 · 物理学 2011-07-29 P. S. Corasaniti , I. Achitouv

The excursion set theory, where density perturbations evolve stochastically with the smoothing scale, provides a method for computing the dark matter halo mass function. The computation of the mass function is mapped into the so-called…

宇宙学与河外天体物理 · 物理学 2012-01-05 Andrea De Simone , Michele Maggiore , Antonio Riotto

If one accounts for correlations between scales, then nonlocal, k-dependent halo bias is part and parcel of the excursion set approach, and hence of halo model predictions for galaxy bias. We present an analysis that distinguishes between a…

宇宙学与河外天体物理 · 物理学 2015-06-05 Marcello Musso , Aseem Paranjape , Ravi K. Sheth

I review the excursion set theory (EST) of dark matter halo formation and clustering. I recount the Press-Schechter argument for the mass function of bound objects and review the derivation of the Press-Schechter mass function in EST. The…

天体物理学 · 物理学 2008-11-26 Andrew R. Zentner

Insight into a number of interesting questions in cosmology can be obtained from the first crossing distributions of physically motivated barriers by random walks with correlated steps. We write the first crossing distribution as a formal…

宇宙学与河外天体物理 · 物理学 2014-07-09 Marcello Musso , Ravi K. Sheth

In the standard excursion set model for the growth of structure, the statistical properties of halos are governed by the halo mass and are independent of the larger scale environment in which the halos reside. Numerical simulations,…

宇宙学与河外天体物理 · 物理学 2015-06-18 Jun Zhang , Chung-Pei Ma , Antonio Riotto

Random walks with a general, nonlinear barrier have found recent applications ranging from reionization topology to refinements in the excursion set theory of halos. Here, we derive the first-crossing distribution of random walks with a…

天体物理学 · 物理学 2009-11-13 Jun Zhang , Lam Hui
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