Related papers: CMB anisotropies from acausal scaling seeds
The residuals of the power spectra of WMAP and Planck's cosmic microwave background (CMB) anisotropies data are known to exhibit a few interesting anomalies at different scales with marginal statistical significance. Combining bottom-up and…
CMB photons passing through a collapsing texture knot receive an energy shift, creating characteristic cold and hot spots on the sky. We calculate the anisotropy pattern produced by collapsing texture knots of arbitrary shape. The texture…
We generalize the treatment of inflationary perturbations to deal with the non-Markovian colored noise emerging from any realistic approach to stochastic inflation. We provide a calculation of the power-spectrum of the gauge-invariant…
We present an analysis of CMB anisotropies induced by global scalar fields in the large N limit. In this limit, the CMB anisotropy spectrum can be determined without cumbersome 3D simulations. We determine the source functions and their…
Cosmologists have embraced a particular ad hoc formula for the primordial power spectrum from inflation for universes with $\Omega_0 < 1$. However, the so-called ``Open Inflation'' models, which are attracting renewed interest in the…
Measurements of the cosmic microwave background (CMB) temperature anisotropies have revealed a dipolar asymmetry in power at the largest scales, in apparent contradiction with the statistical isotropy of standard cosmological models. The…
A new inflationary scenario whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy…
We consider structure formation and CMB anisotropies in a closed universe, both with and without a cosmological constant. The CMB angular power spectrum and the matter transfer function are presented, along with a discussion of their…
Probing correlations among short and long-wavelength cosmological fluctuations is known to be decisive for deepening the current understanding of inflation at the microphysical level. Spectral distortions of the CMB can be caused by…
We argue that the anomalous power asymmetry observed in the cosmic microwave background (CMB) may have originated in a cosmic bounce preceding inflation. In loop quantum cosmology (LQC) the big bang singularity is generically replaced by a…
We present a new approach to constructing inflationary models in closed universes. Conformal embedding of closed-universe models in a de Sitter background suggests a quantisation condition on the available conformal time. This condition…
Amongst the multitude of inflationary models currently available, models that lead to features in the primordial scalar spectrum are drawing increasing attention, since certain features have been found to provide a better fit to the CMB…
This article presents a possible inflation scenario as a consequence of non-minimal gravitational couplings in the Conformal Standard Model. The model consists, in comparison to the SM, of additional right-chiral neutrinos and complex…
The inflationary paradigm is the most successful model that explains the observed spectrum of primordial perturbations. However, the precise emergence of such inhomogeneities and the quantum-to-classical transition of the perturbations has…
Highly symmetric nano-shells are found in many biological systems, such as clathrin cages and viral shells. Several studies have shown that symmetric shells appear in nature as a result of the free energy minimization of a generic…
We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction…
As cosmology rapidly approaches the data-dominated phase of stage IV large scale structure surveys, the modelling of nonlinear scales has become a serious challenge that faces the community, particularly when analysing models beyond $w$CDM.…
In this work we study the imprints of bubble nucleation on primordial inflationary perturbations. We assume that the bubble is formed via the tunneling of a spectator field from the false vacuum of its potential to its true vacuum. We…
In the standard inflationary paradigm the inhomogeneities observed in the CMB arise from quantum fluctuations of an initially homogeneous and isotropic vacuum state. This picture suffers from two well-known weaknesses. First, it assumes…
We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…