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Related papers: Transplanckian signatures in WMAP3?

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We revisit the issue of ripples in the primordial power spectra caused by trans-Planckian physics, and the potential for their detection by future cosmological probes. We find that for reasonably large values of the first slow-roll…

Astrophysics · Physics 2009-11-13 Jan Hamann , Steen Hannestad , Martin S. Sloth , Yvonne Y. Y. Wong

We investigate whether a recently proposed modulation of the power spectrum of primordial density fluctuations generated through transplankian (maybe stringy) effects during inflation can be observed. We briefly review the mechanism leading…

High Energy Physics - Theory · Physics 2014-11-18 L. Bergstrom , U. H. Danielsson

We examine the constraints cosmological observations can place on any trans-Planckian corrections to the primordial spectrum of perturbations underlying the anisotropies in the Cosmic Microwave Background. We focus on models of…

Astrophysics · Physics 2011-05-12 Richard Easther , William H Kinney , Hiranya Peiris

We reconstruct the power spectrum of primordial curvature perturbations by applying a well-validated non-parametric technique employing Tikhonov regularisation to the first data release from the Planck satellite. To improve the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-31 Paul Hunt , Subir Sarkar

The possibility that the cosmic variance outliers present in the recently released WMAP multipole moments are due to oscillations in the primordial power spectrum is investigated. Since the most important contribution to the WMAP likelihood…

Astrophysics · Physics 2008-11-26 Jerome Martin , Christophe Ringeval

We develop an accurate and efficient Bayesian method to reconstruct the primordial power spectrum in a model-independent way, and apply it to the latest cosmic microwave background measurement from Planck mission, and the large scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-28 Xin Wang , Gong-Bo Zhao

The power spectrum of the cosmic microwave background from both the Planck and WMAP data exhibits a slight dip in for multipoles in the range of l=10-30. We show that such a dip could be the result of resonant creation of a massive particle…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-23 G. J. Mathews , M. R. Gangopadhyay , K. Ichiki , T. Kajino

The physical properties of our universe at energy scales above the expansion rate during inflation can affect predictions for the ratio between the amplitudes of the primordial scalar and tensor fluctuations. In particular, we study here…

High Energy Physics - Phenomenology · Physics 2008-11-03 Hael Collins

The vacuum inflation with a boundary condition specified at a short-distance scale in a generally primeval non-flat Universe, and implications of the correspondingly modified primordial power spectrum via the WMAP data are investigated. We…

Astrophysics · Physics 2009-09-28 Jie Ren , Hong-Guang Zhang , Xin-He Meng

This article examines how a breakdown of a locally Lorentz invariant, point-like description of nature at tiny space-time intervals would translate into a distinctive set of signals in the primordial power spectrum generated by inflation.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hael Collins , R. Holman

We reconstruct the primordial spectrum of the curvature perturbation, $P(k)$, from the observational data of the Wilkinson Microwave Anisotropy Probe (WMAP) by the cosmic inversion method developed recently. In contrast to conventional…

Astrophysics · Physics 2009-10-09 Noriyuki Kogo , Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama

Using the most recent data from the WMAP, ACT and SPT experiments, we update the constraints on models with oscillatory features in the primordial power spectrum of scalar perturbations. This kind of features can appear in models of…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Micol Benetti , Stefania Pandolfi , Massimiliano Lattanzi , Matteo Martinelli , Alessandro Melchiorri

In single-field inflationary models with a low sound speed, the orthogonal shape of the primordial bispectrum arises due to partial cancellations between equilateral-type shapes. This fact allows for a speed of sound c_s as low as about…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Sebastien Renaux-Petel

We consider a recently proposed scenario for the generation of primordial cosmological perturbations, the so called Cosmological Slingshot scenario. We firstly obtain a general expression for the Slingshot primordial power spectrum which…

Astrophysics · Physics 2009-01-16 Cristiano Germani , Michele Liguori

The latest cosmological data seem to indicate a significant deviation from scale invariance of the primordial power spectrum when parameterized either by a power law or by a spectral index with non-zero "running". This deviation, by itself,…

Astrophysics · Physics 2011-05-12 Licia Verde , Hiranya V. Peiris

We investigate the ability to constrain oscillatory features in the primordial power spectrum using current and future cosmic microwave background observations. In particular, we study the observability of an oscillation arising from…

Astrophysics · Physics 2011-05-12 Takemi Okamoto , Eugene A. Lim

It seems that new WMAP data requires a fit with a primordial spectrum containig small negative tilt index in addition to the featureless Harrison-Zeldovich- Peebles spectrum thus implying a broken scale invariance. We show that the data…

Astrophysics · Physics 2010-11-11 Davor Palle

We present a minimally-parametric reconstruction of the primordial power spectrum using the most recent cosmic microwave background and large scale structure data sets. Our goal is to constrain the shape of the power spectrum while…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Hiranya V. Peiris , Licia Verde

Quantum gravity effects are expected to modify the primordial density fluctuations produced during inflation and leave their imprint on the cosmic microwave background observed today. We present a new analysis discussing whether these…

Astrophysics · Physics 2008-12-18 Nicolaas E. Groeneboom , Oystein Elgaroy

We use the WMAP 7 data to place constraints on oscillations supplementing an almost scale-invariant primordial power spectrum. Such oscillations are predicted by a variety of models, some of which amount to assuming there is some…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 P. Daniel Meerburg , Ralph Wijers , Jan Pieter van der Schaar
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