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Related papers: Constraining Inflation Models with Spinning Voids

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We present an inflationary model that is geodesically complete and does not suffer from the transplanckian problem. In most inflationary models, massless (conformal) scalar field fluctuations in a deSitter background gives rise to a…

High Energy Physics - Theory · Physics 2009-09-02 Tirthabir Biswas , Stephon Alexander

The space of inflationary models is vast, containing wide varieties of mechanisms, symmetries, and spectra of particles. Consequently, the space of observational signatures is similarly complex. Hence, it is natural to look for boundaries…

High Energy Physics - Theory · Physics 2020-10-29 Daniel Green , Enrico Pajer

We study the conformal invariance of inflationary non-Gaussianities associated with scalar fluctuations in a non-Bunch-Davies initial state, known as the $\alpha$-vacuum, in single-field slow-roll inflation. The $\alpha$-vacuum is a…

High Energy Physics - Theory · Physics 2024-10-29 Arhum Ansari , Pinak Banerjee , Prateksh Dhivakar , Sachin Jain , Nilay Kundu

It has recently been realized that many theories of physics beyond the Standard Model give rise to cosmological histories exhibiting extended epochs of cosmological stasis. During such epochs, the abundances of different energy components…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-17 Keith R. Dienes , Lucien Heurtier , Fei Huang , Tim M. P. Tait , Brooks Thomas

In single-field, slow-roll inflationary models, scalar and tensorial (Gaussian) perturbations are both characterized by a zero mean and a non-zero variance. In position space, the corresponding variance of those fields diverges in the…

General Relativity and Quantum Cosmology · Physics 2014-11-20 I. Agullo , J. Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

We derive a set of no-go theorems and yes-go examples for the parity-odd primordial trispectrum of curvature perturbations. We work at tree-level in the decoupling limit of the Effective Field Theory of Inflation and assume scale invariance…

High Energy Physics - Theory · Physics 2023-03-07 Giovanni Cabass , Sadra Jazayeri , Enrico Pajer , David Stefanyszyn

Observations of the cosmic microwave background do not yet determine whether inflation was driven by a slowly-rolling scalar field or involved another physical mechanism. In this paper we discuss the prospects of using the power spectra of…

High Energy Physics - Theory · Physics 2015-12-10 Daniel Baumann , Daniel Green , Rafael A. Porto

Recently in hep-ph/0605035 and hep-ph/0608138, we have shown that primordial inflation can be embedded within the Minimal Supersymmetric Standard Model, while providing the right amplitude for the density perturbations and a tilted spectrum…

High Energy Physics - Phenomenology · Physics 2007-05-23 Rouzbeh Allahverdi , Anupam Mazumdar

Models of cosmic inflation generically predict a weak but potentially detectable amount of primordial non-Gaussianity (PNG), which can be used to obtain insights into the degrees of freedom during inflation and their interactions. The…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-05 Anton Chudaykin , Mikhail M. Ivanov , Oliver H. E. Philcox

We use a self-consistent modeling of x-ray cluster properties to constrain cosmological scenarios of structure formation in the case of open cosmological models. We first show that an unbiased open model can reproduce present day…

Astrophysics · Physics 2019-08-15 J. Oukbir , A. Blanchard

We propose a new realization of the chaotic inflationary scenario in which the scalar field responsible for inflation also spontaneously breaks the underlying gauge symmetry at a superheavy scale $\sim 10^{15} - 10^{17}\; GeV$. A possible…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Lazarides , Q. Shafi

We investigate if the observed small and nearly scale-invariant primordial cosmic perturbation, i.e. the perturbation amplitude $P_\zeta\sim10^{-9}$ and the spectral index $n_s \simeq 0.965$, is typical in the landscape of vacua after…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Chien-I Chiang , Keisuke Harigaya

Recently it was argued that an inflationary potential yielding power spectra characterized by a scale-invariant tensorial spectral index and a weakly scale-dependent scalar spectral index might account for a generic large-scale structure…

Astrophysics · Physics 2009-11-07 C. A. Terrero-Escalante , A. A. Garcia

We present primordial non-Gaussianity predictions from a new high-precision code for simulating axion-U(1) inflation on a discrete lattice. We measure the primordial scalar curvature power spectrum and bispectrum from our simulations,…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Drew Jamieson , Angelo Caravano , Eiichiro Komatsu

The possibility of thermally induced initial density perturbations in inflationary cosmology is examined. The fluctuation dynamics of a scalar field plus thermal bath system during slow roll is described by a Langevin-like equation.…

Astrophysics · Physics 2016-08-30 Arjun Berera , Li-Zhi Fang

The ability to differentiate between different models of inflation through the imprint of primordial non-Gaussianity (PNG) requires stringent constraints on the local PNG parameter $f_{\text{NL}}^{\text{loc}}$. Upcoming data from the large…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-16 Chandra Shekhar Saraf , David Parkinson

We show that the hybrid inflation is naturally realized in the framework of a supersymmetric axion model, which is consistent with the WMAP observation if the Peccei-Quinn symmetry breaking scale is around 10^{15}GeV. By solving the post…

High Energy Physics - Phenomenology · Physics 2015-03-19 Masahiro Kawasaki , Naoya Kitajima , Kazunori Nakayama

We present a complete computation of the scalar power spectrum in the \emph{inflation without inflaton} (IWI) framework, where the inflationary expansion is driven solely by a de~Sitter (dS) background and scalar fluctuations arise as…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Marisol Traforetti , Mariam Abdelaziz , Daniele Bertacca , Raul Jimenez , Sabino Matarrese , Angelo Ricciardone

We investigate the inflationary consequences of the oscillating dark energy model proposed by Ti\'an [\href{https://doi.org/10.1103/PhysRevD.101.063531}{Phys. Rev. D {\bf 101}, 063531 (2020)}], which aims to solve the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-29 S. X. Tian , Zong-Hong Zhu

We reconsider the original model of quadratic hybrid inflation in light of the WMAP three-year results and study the possibility of obtaining a spectral index of primordial density perturbations, $n_s$, smaller than one from this model. The…

Astrophysics · Physics 2008-11-26 Antonio Cardoso
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