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We calculate the three-point correlation function evaluated at horizon crossing for a set of interacting scalar fields coupled to gravity during inflation. This provides the initial condition for the three-point function of the curvature…

Astrophysics · Physics 2008-11-26 David Seery , James E. Lidsey

An anthropic understanding of the cosmological constant requires that the vacuum energy at late time scans from one patch of the universe to another. If the vacuum energy during inflation also scans, the various patches of the universe…

High Energy Physics - Theory · Physics 2014-11-18 Brian Feldstein , Lawrence J. Hall , Taizan Watari

The origin of the large scale structure in the universe - galaxies, quasars, clusters, voids, sheets - is one of the most important questions in cosmology. One can show that some non-thermal energy density fluctuations must have been…

Astrophysics · Physics 2007-05-23 Mairi Sakellariadou

We perform a detailed analysis on a primordial gravitational-wave background amplified during a Kasner-like pre-inflationary phase allowing for general triaxial anisotropies. It is found that the predicted angular distribution map of…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-11 Yu Furuya , Yuki Niiyama , Yuuiti Sendouda

The curvaton scenario for the generation of the cosmological curvature perturbation on large scales represents an alternative to the standard slow-roll scenario of inflation in which the observed density perturbations are due to…

Astrophysics · Physics 2008-12-18 N. Bartolo , S. Matarrese , A. Riotto , A. Vaihkonen

We revisit the {\it origin of structures problem} of standard Friedmann-Robertson-Walker cosmology to point out an unjustified approximation in the prevalent analysis. We follow common procedures in statistical mechanics to revise the issue…

High Energy Physics - Theory · Physics 2007-05-23 David H. Oaknin

We present simulations of the Cosmic Microwave Background Radiation (CMBR) power spectrum for a class of mixed, non-Gaussian, primordial random fields. We assume a skew positive mixed model with adiabatic inflation perturbations plus…

Astrophysics · Physics 2009-11-10 Ana Paula Andrade , Carlos Alexandre Wuensche , Andre Luiz B. Ribeiro

The statistics of primordial curvature fluctuations are our window into the period of inflation, where these fluctuations were generated. To date, the cosmic microwave background has been the dominant source of information about these…

We present a method for the study of second-order superhorizon perturbations in multi field inflationary models with non trivial kinetic terms. We utilise a change of coordinates in field space to separate isocurvature and adiabatic…

Astrophysics · Physics 2008-11-26 Gerasimos Rigopoulos

We consider primordial fluctuations in thermal inflation scenario. Since the thermal inflation drives about 10 $e$-folds after the standard inflation, the time of horizon-exit during inflation corresponding to the present observational…

High Energy Physics - Theory · Physics 2010-02-18 Masahiro Kawasaki , Tomo Takahashi , Shuichiro Yokoyama

We investigate the cosmic variance of the skewness of the cosmic microwave background (CMB) anisotropies in an inflationary model which leads to the baryon isocurvature scenario for the cosmic structure formation. In this model, the baryon…

Astrophysics · Physics 2016-08-30 Kazuhiro Yamamoto , Misao Sasaki

Primordial fluctuations in the cosmic density are usually assumed to take the form of a Gaussian random field that evolves under the action of gravitational instability. In the early stages, while they have low amplitude, the fluctuations…

Astrophysics · Physics 2009-11-07 Peter Watts , Peter Coles

According to the inflationary scenario, all structure in the Universe can be traced back to quantum fluctuations of the metric and scalar field(s) during inflation. The seeds of this structure can be observed as classical anisotropies in…

Astrophysics · Physics 2008-11-26 Claus Kiefer

We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider both the non-Gaussianities resulting from the…

Astrophysics · Physics 2008-11-26 Matias Zaldarriaga

Primordial non-Gaussianities (PNGs) are imprints in the initial density field sourced by the dynamics of inflation. These dynamics can induce scale dependence, oscillations, and other features in the primordial bispectrum. We analyze a…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-24 Dhayaa Anbajagane , Hayden Lee

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…

Astrophysics · Physics 2011-01-28 Parentani Renaud

Quantum field theory, which is generally used to describe the origin of large-scale gravitational perturbations during cosmic inflation, has been shown to omit an important physical effect in curved space-time, the nonlocal entanglement…

General Relativity and Quantum Cosmology · Physics 2022-04-01 Craig Hogan

Observational tests during the next decade may determine if the evolution of the Universe can be understood from fundamental physical principles, or if special initial conditions, coincidences, and new, untestable physical laws must be…

Astrophysics · Physics 2016-08-30 Paul J. Steinhardt

In this paper we mainly focus on the curvature perturbation generated at the end of multi-field inflation, such as the multi-brid inflation. Since the curvature perturbation is produced on the super-horizon scale, the bispectrum and…

High Energy Physics - Theory · Physics 2010-04-15 Qing-Guo Huang

We study the effect of primordial non-Gaussianity on the development of large-scale cosmic structure using high-resolution N-body simulations. In particular, we focus on the topological properties of the "cosmic web", quantitatively…