Information field theory for cosmological perturbation reconstruction and nonlinear signal analysis

Information field theory for cosmological perturbation reconstruction and non-linear signal analysis

IFT and its application. The concepts of IFT are introduced in Sec. II, where Bayesian methodology, the distinction of physical and information fields, the definition of signal response and noise, as well the design of signal spaces are discussed. The basic IFT formalism including the free theory is introduced in Sec. III, which, according to our judgement, summarizes and unifies the previous k...

Cosmological Perturbation Theory

This is a review on cosmological perturbation theory. After an introduction, it presents the problem of gauge transformation. Gauge invariant variables are introduced and the Einstein and conservation equations are written in terms of these variables. Some examples, especially perfect fluids and scalar fields are presented in detail. The generation of perturbations during inflation is studied. ...

Perturbation Theory of the Cosmological Log-Density Field

Duality in Cosmological Perturbation Theory

Cosmological perturbation equations derived from low-energy effective actions are shown to be invariant under a duality transformation reminiscent of electric-magnetic, strong-weak coupling, S-duality. A manifestly dualityinvariant approximation for perturbations far outside the horizon is introduced, and it is argued to be useful even during a high curvature epoch. Duality manifests itself thr...

Cosmological Perturbation Theory and Structure Formation

These lecture notes discuss several topics in the physics of cosmic structure formation starting from the evolution of small-amplitude fluctuations in the radiation-dominated era. The topics include relativistic cosmological perturbation theory with the scalar-vector-tensor decomposition, the evolution of adiabatic and isocurvature initial fluctuations, microwave background anisotropy, spatial ...