Extended perturbation theory for the local density distribution function
نویسندگان
چکیده
منابع مشابه
Extended Perturbation Theory for the Local Density Distribution Function
Perturbation theory makes it possible to calculate the probability distribution function (PDF) of the large scale density eld in the small variance limit, 1. For top hat smoothing and scale-free Gaussian initial uctuations, the result depends only on the linear variance, linear, and its logarithmic derivative with respect to the ltering scale (nlinear + 3) = d log 2 linear =d log ` (Bernardeau ...
متن کاملDensity field in extended Lagrangian perturbation theory
We analyze the performance of a perturbation theory for nonlinear cosmological dynamics, based on the Lagrangian description of hydrodynamics. In our previous paper, we solved the hydrodynamic equations for a self-gravitating fluid with pressure, given by a polytropic equation of state, using a perturbation method. Then we obtained the first-order solutions in generic background universes and t...
متن کاملThe skewness and kurtosis of the projected density distribution function: validity of perturbation theory
We study the domain of validity of Perturbation Theory (PT), by comparing its predictions for the reduced skewness, s3, and kurtosis, s4, of the projected cosmological density field, with the results of N-body simulations. We investigate models with different linear power spectra and consider as physical applications both angular galaxy catalogues and weak lensing surveys. We first find that th...
متن کاملDensity perturbation in extended inflation
We examine the calculation of density perturbation at large scales in the inflationary scenario. The formula for its magnitude is reviewed from first principles and applied to the original model of extended inflation. Our estimate is an order of magnitude bigger than the earlier ones due to the difference in the time at which the primordial fluctuation is evaluated and to the inclusion of terms...
متن کاملVariational Perturbation Theory for Density Matrices
Variational perturbation theory [1,2] transforms divergent perturbation expansions into convergent ones. The convergence extends to infinitely strong couplings [3], a property which has recently been used to derive critical exponents in field theory without renormalization group methods [4,5]. The theory has first been developed in quantum mechanics for the path integral representation of the f...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1997
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/287.2.241