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Related papers: Non-Gaussianity in two-field inflation beyond the …

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The previously introduced class of two-parametric phenomenological inflationary models in General Relativity in which the slow-roll assumption is replaced by the more general, constant-roll condition is generalized to the case of $f(R)$…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-15 Hayato Motohashi , Alexei A. Starobinsky

Tighter constraints on measurements of primordial non-Gaussianity will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum-the standard method of measuring the local non-Gaussianity-is limited by…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-15 Zahra Gomes , Stefano Camera , Matt J. Jarvis , Catherine Hale , José Fonseca

We analyze the power spectrum and the bispectrum of BOSS galaxy-clustering data using the prediction from the Effective Field Theory of Large-Scale Structure at one-loop order for $\textit{both}$ the power spectrum $\textit{and}$ the…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Guido D'Amico , Matthew Lewandowski , Leonardo Senatore , Pierre Zhang

The bispectrum vanishes for linear Gaussian fields and is thus a sensitive probe of non-linearities and non-Gaussianities in the cosmic density field. Hence, a detection of the bispectrum in the halo density field would enable tight…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-18 Tobias Baldauf , Uros Seljak , Leonardo Senatore

Motivated by trans-Planckian issues in inflation, we determine the Hilbert space and amplitudes of quantum perturbations in the general low-energy effective theory of (multi-)field inflation without relying on the sub-horizon limit. The…

High Energy Physics - Theory · Physics 2026-05-29 Andrea Ambrosi de Magistris , Alberto Salvio

We provide an exact expression for the multi-variate joint probability distribution function of non-Gaussian fields primordially arising from local transformations of a Gaussian field. This kind of non-Gaussianity is generated in many…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Licia Verde , Raul Jimenez , Luis Alvarez-Gaume , Alan F. Heavens , Sabino Matarrese

In constant-roll inflation, the scalar field that drives the accelerated expansion of the Universe is rolling down its potential at a constant rate. Within this framework, we highlight the relations between the Hubble slow-roll parameters…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-08 Alexandros Karam , Luca Marzola , Thomas Pappas , Antonio Racioppi , Kyriakos Tamvakis

We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or non-attractor. We show that the invariance of inflation under space-time diffeomorphisms can be…

High Energy Physics - Theory · Physics 2023-04-13 Rafael Bravo , Gonzalo A. Palma

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

We study primordial fluctuations generated during inflation in a class of models motivated by the DBI Galileons, which are extensions of the DBI action that yield second order field equations. This class of models generalises the DBI…

High Energy Physics - Theory · Physics 2010-12-13 Shuntaro Mizuno , Kazuya Koyama

In the standard slow-roll inflationary cosmology, quantum fluctuations in a single field, the inflaton, generate approximately Gaussian primordial density perturbations. At present, the bispectrum and trispectrum of the density…

High Energy Physics - Phenomenology · Physics 2010-08-03 Kevin T. Engel , Keith S. M. Lee , Mark B. Wise

Preheating can convert superhorizon fluctuations of light scalar fields present at the end of inflation into observable density perturbations. We show in detail how lattice field theory simulations and the separate universes approximation…

Astrophysics · Physics 2008-09-30 Alex Chambers , Arttu Rajantie

The non-Gaussian distribution of primordial perturbations has the potential to reveal the physical processes at work in the very early Universe. Local models provide a well-defined class of non-Gaussian distributions that arise naturally…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 David Wands

We present a generic inference method for inflation models from observational data by the usage of higher-order statistics of the curvature perturbation on uniform density hypersurfaces. This method is based on the calculation of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-25 Sebastian Dorn , Erandy Ramirez , Kerstin E. Kunze , Stefan Hofmann , Torsten A. Enßlin

We show how general initial conditions for small field inflation can be obtained in multi-field models. This is provided by non-linear angular friction terms in the inflaton that provide a phase of non-slow-roll inflation before the…

High Energy Physics - Theory · Physics 2015-06-16 Luis Alvarez-Gaume , Cesar Gomez , Raul Jimenez

In hybrid inflationary models, inflation ends by a sudden instability associated with a steep ridge in the potential. Here we argue that this feature can generate a large contribution to the curvature perturbation on observable scales. This…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-21 David Mulryne , David Seery , Daniel Wesley

We analyse the Planck full-mission cosmic microwave background (CMB) temperature and E-mode polarization maps to obtain constraints on primordial non-Gaussianity (NG). We compare estimates obtained from separable template-fitting, binned,…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-15 Planck Collaboration , Y. Akrami , F. Arroja , M. Ashdown , J. Aumont , C. Baccigalupi , M. Ballardini , A. J. Banday , R. B. Barreiro , N. Bartolo , S. Basak , K. Benabed , J. -P. Bernard , M. Bersanelli , P. Bielewicz , J. R. Bond , J. Borrill , F. R. Bouchet , M. Bucher , C. Burigana , R. C. Butler , E. Calabrese , J. -F. Cardoso , B. Casaponsa , A. Challinor , H. C. Chiang , L. P. L. Colombo , C. Combet , B. P. Crill , F. Cuttaia , P. de Bernardis , A. de Rosa , G. de Zotti , J. Delabrouille , J. -M. Delouis , E. Di Valentino , J. M. Diego , O. Doré , M. Douspis , A. Ducout , X. Dupac , S. Dusini , G. Efstathiou , F. Elsner , T. A. Enßlin , H. K. Eriksen , Y. Fantaye , J. Fergusson , R. Fernandez-Cobos , F. Finelli , M. Frailis , A. A. Fraisse , E. Franceschi , A. Frolov , S. Galeotta , K. Ganga , R. T. Génova-Santos , M. Gerbino , J. González-Nuevo , K. M. Górski , S. Gratton , A. Gruppuso , J. E. Gudmundsson , J. Hamann , W. Handley , F. K. Hansen , D. Herranz , E. Hivon , Z. Huang , A. H. Jaffe , W. C. Jones , G. Jung , E. Keihänen , R. Keskitalo , K. Kiiveri , J. Kim , N. Krachmalnicoff , M. Kunz , H. Kurki-Suonio , J. -M. Lamarre , A. Lasenby , M. Lattanzi , C. R. Lawrence , M. Le Jeune , F. Levrier , A. Lewis , M. Liguori , P. B. Lilje , V. Lindholm , M. López-Caniego , Y. -Z. Ma , J. F. Macías-Pérez , G. Maggio , D. Maino , N. Mandolesi , A. Marcos-Caballero , M. Maris , P. G. Martin , E. Martínez-González , S. Matarrese , N. Mauri , J. D. McEwen , P. D. Meerburg , P. R. Meinhold , A. Melchiorri , A. Mennella , M. Migliaccio , M. -A. Miville-Deschênes , D. Molinari , A. Moneti , L. Montier , G. Morgante , A. Moss , M. Münchmeyer , P. Natoli , F. Oppizzi , L. Pagano , D. Paoletti , B. Partridge , G. Patanchon , F. Perrotta , V. Pettorino , F. Piacentini , G. Polenta , J. -L. Puget , J. P. Rachen , B. Racine , M. Reinecke , M. Remazeilles , A. Renzi , G. Rocha , J. A. Rubiño-Martín , B. Ruiz-Granados , L. Salvati , M. Savelainen , D. Scott , E. P. S. Shellard , M. Shiraishi , C. Sirignano , G. Sirri , K. Smith , L. D. Spencer , L. Stanco , R. Sunyaev , A. -S. Suur-Uski , J. A. Tauber , D. Tavagnacco , M. Tenti , L. Toffolatti , M. Tomasi , T. Trombetti , J. Valiviita , B. Van Tent , P. Vielva , F. Villa , N. Vittorio , B. D. Wandelt , I. K. Wehus , A. Zacchei , A. Zonca

We consider second order inflationary perturbations in the case of two scalar fields, $\sigma$ and the inflaton $\phi$. We derive an expression for the non-Gaussianity of perturbations and apply the results to hybrid inflation. We isolate…

High Energy Physics - Phenomenology · Physics 2009-11-10 Kari Enqvist , Antti Vaihkonen

The discovery of gravitational waves from merging binary black holes has generated considerable interest in examining whether these black holes could have a primordial origin. If a significant number of black holes have to be produced in…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-07 H. V. Ragavendra , L. Sriramkumar

In this paper we investigate the inflationary phenomenology of an Einstein-Gauss-Bonnet theory with the extension of a logarithmic modified $f(R)$ gravity, compatible with the GW170817 event. The main idea of our work is to study different…

General Relativity and Quantum Cosmology · Physics 2021-03-03 S. A. Venikoudis , F. P. Fronimos
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