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Related papers: A Causal Source which Mimics Inflation

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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 show that a moduli space of the form predicted by string theory, lifted by supersymmetry breaking, gives rise to successful inflation for large regions of parameter space without any modification or fine tuning. This natural realization…

High Energy Physics - Phenomenology · Physics 2009-11-10 Kenji Kadota , Ewan D. Stewart

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

In this work we analyze how the spectrum of primordial scalar perturbations is modified, within the emergent universe scenario, when a particular version of the Continuous Spontaneous Localization (CSL) model is incorporated as the…

General Relativity and Quantum Cosmology · Physics 2021-12-03 Gabriel R. Bengochea , María Pía Piccirilli , Gabriel León

The physical mechanism responsible for the emergence of primordial cosmic seeds from a perfect isotropic and homogeneous Universe has not been fully addressed in standard cosmic inflation. To handle this shortcoming, D. Sudarsky et al have…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-26 Gabriel Leon , Alejandro Pujol , Susana J. Landau , Maria Pia Piccirilli

Inflationary scenario based on a renormalizable model of conformal gravity is proposed and primordial spectrum is derived. The sharp fall off of the angular power spectra at low multipoles in the COBE and WMAP observations are explained by…

High Energy Physics - Theory · Physics 2007-05-23 Ken-ji Hamada , Tetsuyuki Yukawa

We examine the degree to which observations of large-scale cosmic microwave background (CMB) polarization can shed light on the puzzling large-scale power modulation in maps of CMB anisotropy. We consider a phenomenological model in which…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Emory F. Bunn , Qingyang Xue , Haoxuan Zheng

We examine the impact of different anisotropic relics on inflation, in particular the predictions on the density perturbations. These relics can be the source of the large scale anomalies in the cosmic microwave background. There are two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Xingang Chen , Razieh Emami , Hassan Firouzjahi , Yi Wang

Detailed analyses of the WMAP data indicate possible oscillatory features in the primordial curvature perturbation, which moreover appears to be suppressed beyond the present Hubble radius. Such deviations from the usual inflationary…

Astrophysics · Physics 2014-11-18 Paul Hunt , Subir Sarkar

The inflationary paradigm is the most successful model that explains the observed spectrum of primordial perturbations. However, the precise emergence of such inhomogeneities and the quantum-to-classical transition of the perturbations has…

General Relativity and Quantum Cosmology · Physics 2016-01-26 Gabriel Leon , Gabriel R. Bengochea

In June 2023, multiple pulsar timing array (PTA) collaborations provided evidence for the existence of a stochastic gravitational-wave background (SGWB). As a significant source of the SGWBs, scalar-induced gravitational waves (SIGWs)…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 Yu-Ting Kuang , Jing-Zhi Zhou , Zhe Chang , Di Wu

I construct a class of single small field models of inflation that can predict an observable gravitational wave signal in the cosmic microwave background anisotropoies, contrary to popular wisdom. The spectral index, its running, the tensor…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-30 Ido Ben-Dayan

We discuss cosmological inflation in the minimal Wess-Zumino model with a single massive chiral supermultiplet. With suitable parameters and assuming a plausible initial condition at the start of the inflationary epoch, the model can yield…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-16 Djuna Croon , John Ellis , Nick E. Mavromatos

It is plausible that the scalar density perturbations are created by a relatively low scale model of inflation which predicts the CMB anisotropy and excites Standard Model baryon and cold dark matter, but negligible gravity waves.…

Astrophysics · Physics 2008-04-03 Rouzbeh Allahverdi , Anupam Mazumdar , Tuomas Multamaki

In the standard cosmological model, the temperature anisotropy of the cosmic microwave background is interpreted as variation in the gravitational potential at the point of emission, due to the emitter being embedded in a region ${\cal C}$…

Astrophysics · Physics 2007-05-23 Richard Lieu

We study a model of inflation where the scalar perturbations are almost gaussian while there is sizable (equilateral) nongaussianity in the tensor sector. In this model, a rolling pseudoscalar gravitationally coupled to the inflaton…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-28 Jessica L. Cook , Lorenzo Sorbo

I discuss the origin of the ``Sakharov oscillations'' (or ``secondary Doppler peaks'') in standard angular power spectra of the Cosmic Microwave Background anisotropies calculated for inflationary models. I contrast this with the production…

Astrophysics · Physics 2007-05-23 Andreas Albrecht

It is proposed that if quantum states of space-time are coherent on null surfaces, holographic Planck-scale fluctuations of inflationary horizons dominate the formation of primordial scalar curvature perturbations. It is shown that the…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-17 Craig Hogan

Causality is a seminal concept in science: Any research discipline, from sociology and medicine to physics and chemistry, aims at understanding the causes that could explain the correlations observed among some measured variables. While…

I give a status report and outlook concerning the use of the cosmic microwave background anisotropies to constrain the inflationary cosmology, and stress its crucial role as an underlying paradigm for the estimation of cosmological…

Astrophysics · Physics 2009-10-30 Andrew R Liddle
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