Linear Evolution of Small Scale Cosmological Density Perturbations
نویسندگان
چکیده
منابع مشابه
Non–Linear Evolution of Cosmological Perturbations
In these lecture notes I review the theory of the non–linear evolution of cosmological perturbations in a self–gravitating collisionless medium, with vanishing vorticity. The problem is first analyzed in the context of the Newtonian approximation, where the basic properties of the Zel’dovich, frozen–flow and adhesion algorithms are introduced. An exact general relativistic formalism is then pre...
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We present a novel approach, based entirely on the gravitational potential, for studying the evolution of non-linear cosmological matter perturbations. Starting from the perturbed Einstein equations, we integrate out the non-relativistic degrees of freedom of the cosmic fluid and obtain a single closed equation for the gravitational potential. We then verify the validity of the new equation by ...
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Through analytic techniques verified by numerical calculations, we establish general relations between the matter and cosmic microwave background (CMB) power spectra and their dependence on cosmological parameters on small scales. Fluctuations in the CMB, baryons, cold dark matter (CDM), and neutrinos receive a boost at horizon crossing. Baryon drag on the photons causes alternating acoustic pe...
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The bispectrum B(k1, k2, k3), the three-point function of density fluctuations in Fourier space, is the lowest order statistic that carries information about the spatial coherence of large-scale structures. For Gaussian initial conditions, when the density fluctuation amplitude is small (δ ≪ 1), tree-level (leading order) perturbation theory predicts a characteristic dependence of the bispectru...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1999
ISSN: 0074-1809
DOI: 10.1017/s0074180900132905