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The bispectrum will play an important role in future galaxy surveys. On large scales it is a key probe for measuring primordial non-Gaussianity which can help differentiate between different inflationary models and other theories of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-12 Chris Clarkson , Eline M. de Weerd , Sheean Jolicoeur , Roy Maartens , Obinna Umeh

Tensor non-Gaussianity represents an important future probe of the physics of inflation. Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato , David Wands

We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and dilaton field. An interesting feature of…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Juan Garcia-Bellido , David Wands

In a variety of inflation models the motion of the inflaton may trigger the production of some non-inflaton particles during inflation, for example via parametric resonance or a phase transition. Particle production during inflation leads…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-07 Neil Barnaby , Zhiqi Huang

Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the…

High Energy Physics - Theory · Physics 2014-03-26 Toshifumi Noumi , Masahide Yamaguchi

We examine the squeezed limit of the bispectrum when a light scalar with arbitrary non-derivative self-interactions is coupled to the inflaton. We find that when the hidden sector scalar is sufficiently light ($m\lesssim0.1\,H$), the…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-10 Béatrice Bonga , Suddhasattwa Brahma , Anne-Sylvie Deutsch , Sarah Shandera

Future cosmic microwave background polarization experiments will search for evidence of primordial tensor modes at large angular scales, in the multipole range $4 \leq \ell \leq 50.$ Because in that range there is some mild evidence of…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-26 Gonzalo A. Palma , Bastian Pradenas , Walter Riquelme , Spyros Sypsas

The existence of light particles with spin during inflation is prohibited by the Higuchi bound. This conclusion can be evaded if one considers states with a sizeable coupling with the inflaton foliation, since this breaks the de Sitter…

High Energy Physics - Theory · Physics 2018-10-17 Lorenzo Bordin , Paolo Creminelli , Andrei Khmelnitsky , Leonardo Senatore

Primordial inflation may represent the most powerful collider to test high-energy physics models. In this paper we study the impact on the inflationary power spectrum of the comoving curvature perturbation in the specific model where…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Nicola Bartolo , Alex Kehagias , Michele Liguori , Antonio Riotto , Maresuke Shiraishi , Vittorio Tansella

We study the predictions of anomalous inflationary models on the abundance of structures in large scale structure observations. The anomalous features encoded in primordial curvature perturbation power spectrum are (a): localized feature in…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-30 Shant Baghram , Ali Akbar Abolhasani , Hassan Firouzjahi , Mohammad Hossein Namjoo

We investigate the degree to which the Cosmic Microwave Background (CMB) can be used to constrain primordial non-Gaussianity coming from the presence of spinning particles coupled to the inflaton. We compute the $\langle TTT \rangle$ and…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-09 Lorenzo Bordin , Giovanni Cabass

We investigate expected constraints on equilateral-type primordial non-Gaussianities from future/ongoing imaging surveys, making use of the fact that they enhance the halo/galaxy bispectrum on large scales. As model parameters to be…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Ichihiko Hashimoto , Shuntaro Mizuno , Shuichiro Yokoyama

The most stringent bounds on the absolute neutrino mass scale come from cosmological data. These bounds are made possible because massive relic neutrinos affect the expansion history of the universe and lead to a suppression of matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-07 Roland de Putter , Eric V. Linder , Abhilash Mishra

We study effects of presence of a small amount of so-called anisotropic solid remnant in the early post-inflationary Universe dominated by radiation. This model is inspired by solid inflation and its generalizations with matter described…

General Relativity and Quantum Cosmology · Physics 2025-10-01 Peter Mészáros , Daniel Račko

Features in the primordial power spectrum represent the imprinted signal in the density perturbations of the physics and evolution of the early Universe. A measurement of such signals will represents the need to go beyond the minimal…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-23 Mario Ballardini , Fabio Finelli , Federico Marulli , Lauro Moscardini , Alfonso Veropalumbo

We show that inflationary models with broken rotational invariance generate testable off-diagonal signatures in the correlation between the $\mu$-type distortion and temperature fluctuations of the cosmic microwave background. More…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Maresuke Shiraishi , Michele Liguori , Nicola Bartolo , Sabino Matarrese

(abridged) We explore the statistical properties of non-linear cosmic structures in a flat $\Lambda$CDM cosmology in which the index of the primordial power spectrum for scalar perturbations is allowed to depend on the scale. Within the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. Fedeli , F. Finelli , L. Moscardini

A massive scalar field in a curved spacetime can propagate along the light cone, a causal pathology, which can, in principle, be eliminated only if the scalar couples conformally to the Ricci curvature of spacetime. This property mandates…

General Relativity and Quantum Cosmology · Physics 2013-09-20 Valerio Faraoni

To compute the spectrum of bubble collisions seen by an observer in an eternally-inflating multiverse, one must choose a measure over the diverging spacetime volume, including choosing an "initial" hypersurface below which there are no…

High Energy Physics - Theory · Physics 2015-05-30 Michael P. Salem

We investigate quantum entanglement of a scalar field in the inflationary universe. By introducing a bipartite system using a lattice model of scalar field, we apply the separability criterion based on the partial transpose operation and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yasusada Nambu