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Signatures of heavy particles during inflation are exponentially suppressed by the Boltzmann factor when the masses are far above the Hubble scale. In more realistic scenarios, however, scale-dependent features may change this conventional…

High Energy Physics - Theory · Physics 2025-05-27 Dong-Gang Wang , Bowei Zhang

It is generally expected that heavy fields are present during inflation, which can leave their imprint in late-time cosmological observables. The main signature of these fields is a small amount of distinctly shaped non-Gaussianity, which…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-05 P. Daniel Meerburg , Moritz Münchmeyer , Julian B. Muñoz , Xingang Chen

The general kind noncanonical warm inflation is introduced and its total non-Gaussianity of perturbation on uniform energy density hypersurfaces is studied. The total non-Gaussianity contains two complementary parts: the three- and the…

General Relativity and Quantum Cosmology · Physics 2019-12-19 Xiao-Min Zhang , Kai Li , Hong-Yang Ma , Qian Liu , Jian-Yang Zhu

We apply the Effective Field Theory of Inflation to study the case where the continuous shift symmetry of the Goldstone boson \pi is softly broken to a discrete subgroup. This case includes and generalizes recently proposed String Theory…

High Energy Physics - Theory · Physics 2015-06-03 Siavosh R. Behbahani , Anatoly Dymarsky , Mehrdad Mirbabayi , Leonardo Senatore

We compute correlation functions of the primordial density perturbations when they couple to a gapless, strongly coupled sector of spectator fields -- ``unparticles" -- during inflation. We first derive a four-point function of conformally…

High Energy Physics - Theory · Physics 2026-04-21 Guilherme L. Pimentel , Chen Yang

We discuss the possible existence of features in both the primordial power spectrum and bispectrum generated during a stage of single field cosmic inflation. We argue that there are two main classes of features: those produced by a sudden…

High Energy Physics - Theory · Physics 2015-06-23 Gonzalo A. Palma

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

Many inflation models predict that primordial density perturbations have a nonzero three-point correlation function, or bispectrum in Fourier space. Of the several possibilities for this bispectrum, the most commmon is the local-model…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Razieh Emami , Emanuela Dimastrogiovanni , Jens Chluba , Marc Kamionkowski

We demonstrate an approach that allows separating two-point correlations created by a Gaussian random field from correlations created by cosmic foregrounds such as polarized dust emission, gravitational lensing and other non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 D. I. Novikov , K. O. Parfenov

We present theoretical and observational studies of non-Gaussian fluctuations in CMB, by using the angular bispectrum and trispectrum. We predict the primary angular bispectrum from inflation, and forecast how well we can measure the…

Astrophysics · Physics 2007-05-23 Eiichiro Komatsu

This is a review of models of inflation and of their predictions for the primordial non-Gaussianity in the density perturbations which are thought to be at the origin of structures in the Universe. Non-Gaussianity emerges as a key…

Astrophysics · Physics 2009-11-10 N. Bartolo , E. Komatsu , S. Matarrese , A. Riotto

Many statistics available to constrain non-Gaussianity from inflation are simplest to use under the assumption that the curvature correlation functions are hierarchical. That is, if the n-point function is proportional to the (n-1) power of…

Astrophysics · Physics 2010-04-30 Sarah Shandera

We study the effect of quantum decoherence on the inflationary cosmological perturbations. This process might imprint specific observational signatures revealing the quantum nature of the inflationary mechanism being related to the…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-03 Aoumeur Daddi Hammou , Nicola Bartolo

It is well known that enhancement in the primordial scalar perturbations over small scales generates detectable amplitudes of secondary gravitational waves (GWs), by sourcing the tensor perturbations at the second order. These stochastic…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-06 H. V. Ragavendra

We identify a characteristic pattern in the scalar-induced stochastic gravitational wave background from particle production during inflation. If particle production is sufficiently efficient, the scalar power spectrum exhibits…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-24 Jacopo Fumagalli , Sébastien Renaux-Petel , Lukas T. Witkowski

Bouncing scenarios offer an alternative to the inflationary paradigm for the generation of perturbations in the early universe. Recently, there has been a surge in interest in examining the issue of primordial magnetogenesis in the context…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-30 Debika Chowdhury , L. Sriramkumar , Marc Kamionkowski

We extend the formalism of time-sliced perturbation theory (TSPT) for cosmological large-scale structure to include non-Gaussian initial conditions. We show that in such a case the TSPT interaction vertices acquire new contributions whose…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-20 Anagha Vasudevan , Mikhail M. Ivanov , Sergey Sibiryakov , Julien Lesgourgues

We discuss new consistency relations for single field models of inflation capable of generating primordial black holes (PBH), and their observational implications for CMB $\mu$-space distortions. These inflationary models include a short…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Ogan Özsoy , Gianmassimo Tasinato

Cosmic inflation provides a window to the highest energy densities accessible in nature, far beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the inflationary era and its observational probes may…

(Shortened abstract) While a featureless, nearly scale invariant, primordial scalar power spectrum fits the most recent CMB data rather well, certain features in the spectrum are known to lead to a better fit to the data (although, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jerome Martin , L. Sriramkumar