English
Related papers

Related papers: A New Window on Primordial non-Gaussianity

200 papers

This paper explores a novel application of spherical convolutional neural networks (CNNs) to detect primordial non-Gaussianity in the cosmic microwave background (CMB), a key probe of inflationary dynamics. While effective, traditional…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Jorik Melsen , Thomas Flöss , P. Daniel Meerburg

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…

High Energy Physics - Phenomenology · Physics 2019-03-27 Haipeng An , Mark B. Wise , Zipei Zhang

Possible signatures of primordial magnetic fields on the Cosmic Microwave Background (CMB) temperature and polarization anisotropies are reviewed. The signals that could be searched for include excess temperature anisotropies particularly…

Astrophysics · Physics 2009-11-11 Kandaswamy Subramanian

Gaussianity of the cosmological perturbations in the universe is one of the key predictions of standard inflation, but it is violated by other models of structure formation such as topological defects. We present the first test of the…

Silk damping of primordial small-scale perturbations in the photon-baryon fluid due to diffusion of photons inevitably creates spectral distortions in the CMB. With the proposed CMB experiment PIXIE it might become possible to measure these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jens Chluba , Rishi Khatri , Rashid A. Sunyaev

The dissipation of small-scale perturbations in the early universe produces a distortion in the blackbody spectrum of cosmic microwave background photons. In this work, we propose to use these distortions as a probe of the microphysics of…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 James A. D. Diacoumis , Yvonne Y. Y. Wong

Primordial oscillatory features in the power spectrum of curvature perturbations are sensitive probes of the dynamics of the early Universe and can provide insights beyond the standard inflationary scenario. While these features have been…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Mario Ballardini , Nicola Barbieri

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

Primordial non-Gaussianity arising from inflationary models is a unique probe of non-trivial dynamics of the inflaton field and its interactions with other fields. Often when examining and constraining the scalar non-Gaussianity arising…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-17 Barnali Das , H. V. Ragavendra

Observations by Planck indicate that CMB anisotropies are consistent with predictions of nearly Gaussian primordial perturbations as the one generated in slow-roll inflation. On the other hand, loop quantum cosmology (LQC) generates a…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-02 Roshna K , V. Sreenath

We study the effects of instrumental systematics on the estimation of primordial non-Gaussianity using the cosmic microwave background (CMB) bispectrum from both the temperature and the polarization anisotropies. For temperature systematics…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-07 Meng Su , Amit P. S. Yadav , Meir Shimon , Brian G. Keating

The small-scale crisis, discrepancies between observations and N-body simulations, may imply suppressed matter fluctuations on subgalactic distance scales. Such a suppression could be caused by some early-universe mechanism (e.g., broken…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-05 Tomohiro Nakama , Jens Chluba , Marc Kamionkowski

We study the cosmological information contained in the Minkowski Functionals (MFs) of weak gravitational lensing convergence maps. We show that the MFs provide strong constraints on the local type primordial non-Gaussianity parameter f_NL.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Masato Shirasaki , Naoki Yoshida , Takashi Hamana , Takahiro Nishimichi

The cosmic microwave background (CMB) bispectrum is a well-known probe of the non-Gaussianity of primordial perturbations. Just as the intervening large-scale structure modifies the CMB angular power spectrum through weak gravitational…

Astrophysics · Physics 2008-11-26 Asantha Cooray , Devdeep Sarkar , Paolo Serra

Standard CMB analysis assumes a direct deterministic mapping between the multipole probed by the CMB $\ell$ and the primordial wavenumber $k$. Since the recombination era has a finite duration, this mapping is probabilistic by construction.…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-20 V. K. Oikonomou

Upcoming cosmic microwave background (CMB) data can be used to explore harmonic 3-point functions that involve the B-mode component of the CMB polarization signal. We focus on bispectra describing the non-Gaussian correlation of the B-mode…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Adriaan J. Duivenvoorden , P. Daniel Meerburg , Katherine Freese

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

The next generation of ground-based CMB experiments aim to measure temperature and polarization fluctuations up to $\ell_{\rm max} \approx 5000$ over half of the sky. Combined with Planck data on large scales, this will provide improved…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 William R. Coulton , P. Daniel Meerburg , David G. Baker , Selim Hotinli , Adriaan J. Duivenvoorden , Alexander van Engelen

The issue of non-Gaussianity is not only related to distinguishing the theories of the origin of primordial fluctuations, but also crucial for the determination of cosmological parameters in the framework of inflation paradigm. We present…

Astrophysics · Physics 2009-11-10 Lung-Yih Chiang , Pavel D. Naselsky

The forthcoming Planck experiment will provide high sensitivity polarization measurements that will allow us to further tighten the f_NL bounds from the temperature data. Monte Carlo simulations of non-Gaussian CMB maps have been used as a…