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Related papers: Finite inflation in curved space

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We present cosmological constraints from Planck 2015 data for a universe that is kinetically dominated at very early times. We perform a Markov chain Monte Carlo analysis to estimate parameters and use nested sampling to determine the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-10 L. T. Hergt , W. J. Handley , M. P. Hobson , A. N. Lasenby

Recently, the Planck 2013 results showed possible evidence for a dipolar power modulation of the CMB temperature fluctuations at low--(\ell) multipoles. This anomaly might imply certain deviations from statistical isotropy. To incorporate…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-24 Zhe Chang , Sai Wang

We propose an inflationary primordial feature model that can explain both the large and small-scale anomalies in the currently measured cosmic microwave background (CMB) anisotropy spectra, revealing a clip of adventurous history of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-15 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra

Cosmological inflation remains to be a unique mechanism of generation of plausible initial conditions in the early universe. In particular, it generates the primordial quasiclassical perturbations with power spectrum determined by the…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-23 Yuri Shtanov

Measurements of Cosmic Microwave Background (CMB) anisotropy have served as the best experimental probe of the early universe to date. The inflationary paradigm, inspired in part by the extreme isotropy of the CMB, is now a cornerstone in…

Due to universality and attractor properties, $\alpha$-attractor quintessential inflation establishes direct relations between inflationary observables such as the scalar tilt $n_s$ and the tensor-to-scalar ratio $r$, and late-time dark…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 William Giarè , Eleonora Di Valentino , Eric V. Linder , Enrico Specogna

The BICEP2 collaboration reports a detection of primordial cosmic microwave background (CMB) B-mode with a tensor-scalar ratio $r=0.20^{+0.07}_{-0.05}$ (68% C.L.). However, this result is in tension with the recent Planck limit, $r<0.11$…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-30 Jun-Qing Xia , Yi-Fu Cai , Hong Li , Xinmin Zhang

Inflation elegantly provides initial conditions for the standard model of cosmology, while solving the horizon, flatness, and magnetic monopole problems. Inflationary models make predictions for the tensor-to-scalar ratio $r$ and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 L. Balkenhol , E. Camphuis , F. Finelli , K. Benabed , F. R. Bouchet , J. Carron , S. Galli , E. Hivon , A. R. Khalife , L. Knox , C. L. Reichardt , A. Vitrier , W. L. K. Wu

The effect of spatial curvature on primordial perturbations is controlled by $ \Omega_{K,0}/c_{s}^{2} $, where $ \Omega_{K,0} $ is today's fractional density of spatial curvature and $ c_{s} $ is the speed of sound during inflation. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Guus Avis , Sadra Jazayeri , Enrico Pajer , Jakub Supeł

We study effects of the cosmic string in the D-term inflation model on the cosmic microwave background (CMB) anisotropy. In the D-term inflation model, gauged cosmic string is usually formed, which may significantly affect the CMB…

High Energy Physics - Phenomenology · Physics 2009-11-10 Motoi Endo , Masahiro Kawasaki , Takeo Moroi

We revisit an inflationary scenario in which primordial inhomogeneities arise from a quantum collapse, a stochastic mechanism described in the context of quantum collapse theories in its continuous version and within semiclassical gravity.…

General Relativity and Quantum Cosmology · Physics 2026-03-04 María Pía Piccirilli , Gabriel León , Rosa-Laura Lechuga-Solis , Daniel Sudarsky

The leading candidate for the very early universe is described by a period of rapid expansion known as inflation. While the standard paradigm invokes a single slow-rolling field, many different models may be constructed which fit the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-30 D. M. Regan

We analyze the temperature three--point correlation function and the skewness of the Cosmic Microwave Background (CMB), providing general relations in terms of multipole coefficients. We then focus on applications to large angular scale…

Astrophysics · Physics 2009-10-22 A. Gangui , F. Lucchin , S. Matarrese , S. Mollerach

In inflation cosmologies, cosmic structure develops through the gravitational instability of the inevitable quantum noise in primordial scalar fields. I show how the acceleration of the universe defines the shape of the primordial spectrum…

Astrophysics · Physics 2009-09-25 J. Richard Bond

The anisotropies of the cosmic microwave background (CMB) are computed for the half-turn space E_2 which represents a compact flat model of the Universe, i.e. one with finite volume. This model is inhomogeneous in the sense that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 R. Aurich , S. Lustig

The lack of correlations on the large scale cosmic microwave background (CMB) anisotropy provides a potential window to probe beyond the standard inflationary scenario. In this paper, we investigate the primordial power spectrum based on…

General Relativity and Quantum Cosmology · Physics 2019-03-29 Pisin Chen , Hsiao-Heng Yeh , Dong-han Yeom

The bispectrum of primordial curvature perturbations in the squeezed configuration, in which one wavenumber, $k_3$, is much smaller than the other two, $k_3\ll k_1\approx k_2$, plays a special role in constraining the physics of inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-07 Maresuke Shiraishi , Eiichiro Komatsu , Marco Peloso , Neil Barnaby

The curl-modes of Cosmic Microwave Background (CMB) polarization probe horizon-scale primordial gravitational waves related to inflation. A significant source of confusion is expected from a lensing conversion of polarization related to…

Astrophysics · Physics 2009-11-10 Asantha Cooray

Very small mean curvature is a robust prediction of inflation worth rigorous checking. Since current constraints are derived from determinations of the angular-diameter distance to the CMB last-scattering surface, which is also affected by…

Astrophysics · Physics 2008-11-26 Lloyd Knox
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