相关论文: Super-horizon Perturbations and CMBA
The observed power spectrum of the cosmic microwave background (CMB) is consistent with inflationary cosmology, which predicts a nearly scale-invariant power spectrum of quantum fluctuations of the inflaton field as they exit the Hubble…
Recent detections of cosmic microwave background (CMB) anisotropy at half-degree angular scales show considerable scatter in the reported amplitude even at similar angular resolution. We use Monte Carlo techniques to simulate the current…
We review the present status of Cosmic Microwave Background (CMB) anisotropy observations and discuss the main related astrophysical issues, instrumental effects and data analysis techniques. We summarise the balloon-borne and ground-based…
Cosmic microwave background (CMB) anisotropy may result from both scalar and tensor perturbations. For a sufficiently narrow range of angular scales, CMB perturbations can be characterized by four parameters. Results from the Cosmic…
Cosmological inflation is the dominating paradigm to account for observations of the Cosmic Microwave Background (CMB). In this thesis, we study the phenomenology of a class of particularly well motivated models of inflation, known under…
Recent observations have identified a significant 4.9$\sigma$ tension between the cosmic dipole inferred from galaxy number counts and that derived from the Cosmic Microwave Background (CMB), suggesting a potential deviation from the…
Gravitational lensing, caused by matter perturbations along the line-of-sight to the last scattering surface, can modify the shape of the cosmic microwave background (CMB) anisotropy power spectrum. We discuss the detectability of lensing…
In the near future, observations of the cosmic microwave background (CMB) anisotropies will provide accurate determinations of many fundamental cosmological parameters. In this paper, we analyse degeneracies among cosmological parameters to…
Quantum fluctuations during inflation may be responsible for temperature anisotropies in the cosmic microwave background (CMB). Observations of CMB anisotropies can be used to falsify many currently popular models. In this paper we discuss…
If cosmological perturbations in our Hubble sized volume are nongaussian, then they will be coupled to any larger perturbation modes outside our Hubble volume. This has important consequences for modeling inflation: the scalar power…
The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…
The anisotropies of the cosmic microwave background (CMB) are computed for the half-turn space E_2 which represents a compact flat model of the Universe, i.e. one with finite volume. This model is inhomogeneous in the sense that the…
Observers have demonstrated that it is now feasible to measure the cosmic microwave background (CMB) temperature at high redshifts. We explore the possible constraints on cosmology which might ultimately be derived from such measurements.…
Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard…
Gravitational interaction of cosmic microwave background (CMB) photons with matter perturbations present along the line-of-sight to the surface of last scattering modifies the shape of the CMB anisotropy power spectrum. Here I focus on…
Many observations in recent times have shown evidence against the standard assumption of isotropy in the Big Bang model. Introducing a superhorizon scalar metric perturbation has been able to explain some of these anomalies. In this work,…
The Cosmic Microwave Background (CMB) physics can be used to constrain the dark energy dynamics: B modes of the polarization of the diffuse CMB emission as well as the polarized signal towards clusters of galaxies are sensitive to the…
In view of the growing tension between the dipole anisotropy of number counts of cosmologically distant sources and of the cosmic microwave background (CMB), we investigate the number count dipole induced by primordial perturbations with…
We discuss the question to what degree the geometrical structure and the matter content of the universe at scales exceeding the present Hubble horizon is constrained by cosmological observations, in particular by measurements of the cosmic…
The effect of gravitational lensing on cosmic microwave background (CMB) anisotropies is investigated using the power spectrum approach. The lensing effect can be calculated in any cosmological model by specifying the evolution of…