Results 271 to 278 of about 60,199 (278)
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2018
Abstract This chapter describes the first steps toward an understanding of large structures, which are observed in the universe at all scales—galaxies, groups of galaxies, and galactic clusters. It does so by studying the evolution of perturbations at linear order in Friedmann–Lemaître spacetimes.
Nathalie Deruelle, Jean-Philippe Uzan
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Abstract This chapter describes the first steps toward an understanding of large structures, which are observed in the universe at all scales—galaxies, groups of galaxies, and galactic clusters. It does so by studying the evolution of perturbations at linear order in Friedmann–Lemaître spacetimes.
Nathalie Deruelle, Jean-Philippe Uzan
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Braneworld cosmological perturbations
EAS Publications Series, 2008A longstanding problem in braneworld cosmology is quantifying the dynamics of cosmological perturbations. This is because, unlike the 4-dimensional case, fluctuations are governed by non-separable partial differential equations (PDEs). We have developed a fast and accurate code to solve the relevant equations of motion, and hence extract observational ...
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Local gauge-invariant cosmological perturbations
Physical Review D, 1992We develop a gauge-invariant formalism suitable for the study of cosmological perturbations induced by defects. It consists in remolding the well-known Bardeen formalism into a local and gauge-invariant theory formulated in configuration space. Bardeen's variables are first combined into local and gauge-invariant variables with simple geometric ...
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