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Related papers: Direct search for features in the primordial bispe…

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We study the generation of sharp features in the primordial spectra within the framework of effective field theory of inflation, wherein curvature perturbations are the consequence of the dynamics of a single scalar degree of freedom. We…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-29 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

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…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-20 Yi-Fu Cai , Wen Zhao , Yang Zhang

Mainly used to set constraints on cosmological parameters, CMB anisotropies can give information on primordial universe. Unfortunately, initial conditions and late time cosmology are degenerated. I focus on the effect of the shape of the…

Astrophysics · Physics 2007-05-23 Marian Douspis

Non-linear effects in the early Universe generate non-zero bispectra of the cosmic microwave background (CMB) temperature and polarization, even in the absence of primordial non-Gaussianity. In this paper, we compute the contributions from…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-09 Pedro Carrilho , Karim A. Malik

We explore the correlations between correlation functions of the primordial curvature perturbation produced during inflation. We find that for general single field inflation, other than the source terms which depend on the model details,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Jinn-Ouk Gong , Koenraad Schalm , Gary Shiu

We present the implementation of a fast estimator for the full dark matter bispectrum of a three-dimensional particle distribution relying on a separable modal expansion of the bispectrum. The computational cost of accurate bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 M. M. Schmittfull , D. M. Regan , E. P. S. Shellard

Inspired by the study of mild transient reductions in the speed of sound of the adiabatic mode during inflation, we search for a primordial localized feature imprinted in cosmic microwave background and large-scale structure formation…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-19 Bin Hu , Jesús Torrado

Different inflationary models predict oscillatory features in the primordial power spectrum. These can leave an imprint on both the cosmic microwave background (CMB) and the large-scale structure (LSS) of our Universe, that can be searched…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-15 Chenxiao Zeng , Ely D. Kovetz , Xuelei Chen , Yan Gong , Julian B. Muñoz , Marc Kamionkowski

We examine the potential of polarization bispectra of the cosmic microwave background (CMB) to constrain primordial magnetic fields (PMFs). We compute all possible bispectra between temperature and polarization anisotropies sourced by PMFs…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-07 Maresuke Shiraishi

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…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra

Under the presence of anisotropic sources in the inflationary era, the trispectrum of the primordial curvature perturbation has a very specific angular dependence between each wavevector that is distinguishable from the one encountered when…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-12 Maresuke Shiraishi , Nicola Bartolo , Michele Liguori

A complete numerical calculation of the temperature anisotropies and the polarization of the cosmic microwave background (CMB) is presented for a non zero cross correlation of a stochastic magnetic field with the primordial curvature…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-15 Kerstin E. Kunze

We study quasi-matter bounce cosmology in light of Planck cosmic microwave background (CMB) angular anisotropy measurements along with the BICEP2/Keck Array data. We propose a new primordial scalar power spectrum by considering a linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-08 Mohammad Arab , Mohsen Khorasani

We revisit the Cosmic Microwave Background (CMB) constraints on the spatial curvature of the Universe, assessing how they change when the curvature parameter and the primordial inflationary scalar spectrum are treated consistently within…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-01 Enrico Specogna , Tatevik Vardanyan , William Giarè , Eleonora Di Valentino

The spectrum of primordial fluctuations from inflation can be obtained using a mathematically controlled, and systematically extendable, uniform approximation. Closed-form expressions for power spectra and spectral indices may be found…

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Maresuke Shiraishi

Primordial black holes (PBHs) can be both candidates of dark matter and progenitors of binary black holes (BBHs) detected by the LIGO-Virgo-KAGRA collaboration. Since PBHs could form in the very early Universe through the gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Li-Ming Zheng , Zhengxiang Li , Zu-Cheng Chen , Huan Zhou , Zong-Hong Zhu

We provide a simple but robust bound on the primordial curvature perturbation in the range $10^4 {\rm Mpc}^{-1} < k < 10^5 {\rm Mpc}^{-1}$, which has not been constrained so far unlike low wavenumber modes. Perturbations on these scales…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-11 Tomohiro Nakama , Teruaki Suyama , Jun'ichi Yokoyama

Two different predictions for the primordial curvature fluctuation bispectrum are compared through their effects on the Cosmic Microwave Background temperature fluctuations. The first has a local form described by a single parameter f_{NL}.…

Astrophysics · Physics 2009-06-23 Ian G Moss , Chris M Graham

We calculate the cosmic microwave background temperature bispectrum from cosmic strings, for the first time including the contributions from the last scattering surface, using a well-established Gaussian model for the string energy-momentum…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-21 Donough Regan , Mark Hindmarsh