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Related papers: Probing the Inflaton Potential with SKA

200 papers

We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant ($H_{0} = 73.00\pm 1.75$ km s $^{-1}$ Mpc$^{-1}$). We constrain the primordial power…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Rui-Yun Guo , Xin Zhang

The SKA will discover tens of thousands of pulsars and provide unprecedented data quality on these, as well as the currently known population, due to its unrivalled sensitivity. Here, we outline the state of the art of our understanding of…

We investigate the problem of fine tuning of the potential in the KKLMMT warped flux compactification scenario for brane-antibrane inflation in Type IIB string theory. We argue for the importance of an additional parameter psi_0…

High Energy Physics - Theory · Physics 2009-11-11 James M. Cline , Horace Stoica

In the light of the recent results concerning CMB observations and GW detection we address the question of whether it is possible, in a self-consistent inflationary framework, to simultaneously generate a spectrum of scalar metric…

General Relativity and Quantum Cosmology · Physics 2016-12-08 M. Gasperini

We measure the Cosmic Microwave Background (CMB) skewness power spectrum in $\textit{Planck}$, using frequency maps of the HFI instrument and the Sunyaev-Zel'dovich (SZ) component map. The two-to-one skewness power spectrum measures the…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-01 Nicholas Timmons , Asantha Cooray , Chang Feng , Brian Keating

The SKA era is set to revolutionize our understanding of neutral hydrogen (HI) in individual galaxies out to redshifts of z~0.8; and in the z > 6 intergalactic medium through the detection and imaging of cosmic reionization. Direct HI…

Astrophysics of Galaxies · Physics 2017-08-23 Roger Deane , Danail Obreschkow , Ian Heywood

SKA is a new technology radio-telescope array, about two orders of magnitude more sensitive and rapid in sky surveys than present instruments. It will probe the dark age of the universe, just afer recombination, and during the epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Francoise Combes

The advent of new observational facilities in the last two decades has allowed the rapid discovery and high-resolution optical imaging of many strong lens systems from galaxy to cluster scales, as well as their spectroscopic follow-up.…

Astrophysics · Physics 2009-11-10 L. V. E. Koopmans , I. W. A. Browne , N. J. Jackson

We investigate an ability of the exponential power-law inflation to be phenomenologically correct model of the early universe. GR scalar cosmology equations we study in Ivanov-Salopek-Bond (or Hamilton-Jacobi like) representation where the…

General Relativity and Quantum Cosmology · Physics 2025-01-22 I. V. Fomin , S. V. Chervon

We construct a pipeline for simulating weak lensing cosmology surveys with the Square Kilometre Array (SKA), taking as inputs telescope sensitivity curves; correlated source flux, size and redshift distributions; a simple ionospheric model;…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Anna Bonaldi , Ian Harrison , Stefano Camera , Michael L. Brown

Slow-roll inflation may simultaneously solve the horizon problem and generate a near scale-free fluctuation spectrum P(k). These two processes are intimately connected via the initiation and duration of the inflationary phase. But a recent…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Jingwei Liu , Fulvio Melia

We minimally extend the SM with a Z$_2$ symmetric potential containing a single scalar field, serving as our inflaton with a quartic self-coupling. In the model we have symmetry breaking in both sectors, and with the addition of an…

High Energy Physics - Phenomenology · Physics 2021-10-27 Fedor Bezrukov , Abigail Keats

HI 21-cm absorption spectroscopy provides a unique probe of the cold neutral gas in normal and active galaxies from redshift z > 6 to the present day. We describe the status of HI absorption studies, the plans for pathfinders/precursors,…

Astrophysics of Galaxies · Physics 2015-01-07 Raffaella Morganti , Elaine M. Sadler , Stephen J. Curran , the SKA HI SWG Members

We update the search for features, due to transient reductions in inflaton's speed of sound, in the Cosmic Microwave Background (CMB) angular power spectrum using Planck 2018 temperature, polarization and lensing data. We develop a new…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Guadalupe Cañas-Herrera , Jesús Torrado , Ana Achúcarro

Single-field slow-roll inflation predicts a nearly scale-free power spectrum of perturbations, as observed at the scales accessible to current cosmological experiments. This spectrum is slightly red, showing a tilt $(1-n_s)\sim 0.04$. A…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 Julian B. Muñoz , Ely D. Kovetz , Alvise Raccanelli , Marc Kamionkowski , Joseph Silk

Stacking polarized radio emission in SKA surveys provides statistical information on large samples that is not accessible otherwise due to limitations in sensitivity, source statistics in small fields, and averaging over frequency…

Instrumentation and Methods for Astrophysics · Physics 2015-01-05 J. M. Stil , B. W. Keller

We consider approaches to cosmological parameter estimation in the inflationary cosmology, focussing on the required accuracy of the initial power spectra. Parametrizing the spectra, for example by power-laws, is well suited to testing the…

Astrophysics · Physics 2009-11-07 Samuel M. Leach , Andrew R. Liddle , Jerome Martin , Dominik J. Schwarz

This article is devoted to the study of scalar perturbations in loop quantum cosmology. It aims at clarifying the situation with respect to the way initial conditions are set and to the specific choice of an inflaton potential. Several…

General Relativity and Quantum Cosmology · Physics 2018-10-10 Aurélien Barrau , Pierre Jamet , Killian Martineau , Flora Moulin

We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat $\Lambda$CDM model. Unlike…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama

We first derive the primordial power spectra, spectral indices and runnings of both scalar and tensor perturbations of a flat inflationary universe to the second-order approximations of the slow-roll parameters, in the framework of loop…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Tao Zhu , Anzhong Wang , Klaus Kirsten , Gerald Cleaver , Qin Sheng , Qiang Wu