Related papers: CMB Angular Power Spectrum from Correlated Primord…
We consider cosmic microwave background (CMB) anisotropy in models with quintessence taking into account of isocurvature fluctuation in the quintessence. It is shown that, if the primordial fluctuation of the quintessence has a correlation…
A description of CMB temperature fluctuations beyond the power spectrum is important for verifying models of structure formation, especially in view of forthcoming high-resolution observations. We argue that higher-order statistics of…
We review why the search for a causal explanation of the large scale properties of the universe supports the idea that an extended period of accelerated expansion, called inflation, preceded primordial nucleosynthesis. As a consequence of…
Correlation functions of primordial density fluctuations provide an exciting probe of the physics governing the earliest moments of our Universe. However, the standard approach to compute them is technically challenging. Theoretical…
We study non-Gaussianity, the spectral index of primordial scalar fluctuations and tensor modes in models where fluctuations from the inflaton and the curvaton can both contribute to the present cosmic density fluctuations. Even though…
Primordial magnetic fields lead to non-Gaussian signals in the Cosmic Microwave Background (CMB) even at the lowest order, as magnetic stresses, and the temperature anisotropy they induce, depend quadratically on the magnetic field. In…
It was pointed out recently that in some inflationary models quantum loops containing a scalar of mass $m$ that couples to the inflaton can be the dominant source of primordial non-Gaussianities. We explore this phenomenon in the simplest…
We consider the spectrum of primordial fluctuations produced by inflationary models where the inflaton potential is the sum of two exponential terms. A wide range of spectra result, with the only constraint being that the scalar spectrum…
Current measurements of the temperature and polarization anisotropy power spectra of the Cosmic Microwave Background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm…
The curl-modes of Cosmic Microwave Background (CMB) polarization probe horizon-scale primordial gravitational waves related to inflation. A significant source of confusion is expected from a lensing conversion of polarization related to…
In multiple inflation scenario having two inflations with an intermediate matter-dominated phase, the power spectrum is estimated to be enhanced on scales smaller than the horizon size at the beginning of the second inflation, $k > k_{\rm…
It is well known that processes of first order phase transitions may have occurred in the inflationary era. If one or more occurred well before the end of inflation, the nucleated bubbles are stretched to large scales and the primordial…
In standard inflationary cosmology, scalar and tensor perturbations grew as the Universe expanded and froze when their wavelengths exceeded the Hubble horizon, producing a tell-tale signature in the fluctuation spectrum and amplitude of the…
We study the power spectrum of the mass density perturbations in an inflation scenario that includes thermal dissipation. We show that the condition on which the thermal fluctuations dominate the primordial density perturbations can easily…
The temperature perturbations of the cosmic microwave background radiation (CMB) appear systematically suppressed, at large angular scales, with respect to the prediction of the LambdaCDM concordance model. This behavior might be a glimpse…
The hemispherical power asymmetry in the cosmic microwave background may be explained by the modulation of some primordial cosmological parameter, such as the sound speed of the inflaton. This modulation can be achieved by the perturbation…
We constrain the primordial fluctuation spectrum P(k) by using the new data on the Cosmic Microwave Background (CMB) from the Boomerang and MAXIMA experiments. Our study is based on slow-roll inflationary models, and we consider the…
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…
The prediction of a nearly scale-invariant spectrum of curvature and tensor fluctuations is among the main features of cosmic inflation. The current measurements of the primordial fluctuations in the cosmic microwave background (CMB)…
We use cosmic microwave background (CMB) data from the 9-year WMAP release to derive constraints on monodromy inflation, which is characterized by a linear inflaton potential with a periodic modulation. We identify two possible periodic…