Towards a measurement of the spectral runnings
Abstract
Singlefield slowroll inflation predicts a nearly scalefree power spectrum of perturbations, as observed at the scales accessible to current cosmological experiments. This spectrum is slightly red, showing a tilt (1− n {sub s} )∼ 0.04. A direct consequence of this tilt are nonvanishing runnings α {sub s} = d n {sub s} / dlog k , and β {sub s} = dα {sub s} / dlog k , which in the minimal inflationary scenario should reach absolute values of 10{sup −3} and 10{sup −5}, respectively. In this work we calculate how well future surveys can measure these two runnings. We consider a Stage4 (S4) CMB experiment and show that it will be able to detect significant deviations from the inflationary prediction for α {sub s} , although not for β {sub s} . Adding to the S4 CMB experiment the information from a WFIRSTlike or a DESIlike survey improves the sensitivity to the runnings by ∼ 20%, and 30%, respectively. A spectroscopic survey with a billion objects, such as the SKA, will add enough information to the S4 measurements to allow a detection of α {sub s} =10{sup −3}, required to probe the singlefield slowroll inflationary paradigm. We show thatmore »
 Authors:
 Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States)
 Publication Date:
 OSTI Identifier:
 22676210
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 05; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; COMPARATIVE EVALUATIONS; DETECTION; DISTURBANCES; FORECASTING; GRAVITATIONAL WAVES; INTERFEROMETERS; MASS; PERTURBATION THEORY; RELICT RADIATION; SENSITIVITY; SPECTRA; STOCHASTIC PROCESSES
Citation Formats
Muñoz, Julian B., Kovetz, Ely D., Raccanelli, Alvise, Kamionkowski, Marc, and Silk, Joseph, Email: julianmunoz@jhu.edu, Email: ekovetz1@jhu.edu, Email: alvise@icc.ub.edu, Email: mkamion1@jhu.edu, Email: joseph.silk@physics.ox.ac.uk. Towards a measurement of the spectral runnings. United States: N. p., 2017.
Web. doi:10.1088/14757516/2017/05/032.
Muñoz, Julian B., Kovetz, Ely D., Raccanelli, Alvise, Kamionkowski, Marc, & Silk, Joseph, Email: julianmunoz@jhu.edu, Email: ekovetz1@jhu.edu, Email: alvise@icc.ub.edu, Email: mkamion1@jhu.edu, Email: joseph.silk@physics.ox.ac.uk. Towards a measurement of the spectral runnings. United States. doi:10.1088/14757516/2017/05/032.
Muñoz, Julian B., Kovetz, Ely D., Raccanelli, Alvise, Kamionkowski, Marc, and Silk, Joseph, Email: julianmunoz@jhu.edu, Email: ekovetz1@jhu.edu, Email: alvise@icc.ub.edu, Email: mkamion1@jhu.edu, Email: joseph.silk@physics.ox.ac.uk. Mon .
"Towards a measurement of the spectral runnings". United States.
doi:10.1088/14757516/2017/05/032.
@article{osti_22676210,
title = {Towards a measurement of the spectral runnings},
author = {Muñoz, Julian B. and Kovetz, Ely D. and Raccanelli, Alvise and Kamionkowski, Marc and Silk, Joseph, Email: julianmunoz@jhu.edu, Email: ekovetz1@jhu.edu, Email: alvise@icc.ub.edu, Email: mkamion1@jhu.edu, Email: joseph.silk@physics.ox.ac.uk},
abstractNote = {Singlefield slowroll inflation predicts a nearly scalefree power spectrum of perturbations, as observed at the scales accessible to current cosmological experiments. This spectrum is slightly red, showing a tilt (1− n {sub s} )∼ 0.04. A direct consequence of this tilt are nonvanishing runnings α {sub s} = d n {sub s} / dlog k , and β {sub s} = dα {sub s} / dlog k , which in the minimal inflationary scenario should reach absolute values of 10{sup −3} and 10{sup −5}, respectively. In this work we calculate how well future surveys can measure these two runnings. We consider a Stage4 (S4) CMB experiment and show that it will be able to detect significant deviations from the inflationary prediction for α {sub s} , although not for β {sub s} . Adding to the S4 CMB experiment the information from a WFIRSTlike or a DESIlike survey improves the sensitivity to the runnings by ∼ 20%, and 30%, respectively. A spectroscopic survey with a billion objects, such as the SKA, will add enough information to the S4 measurements to allow a detection of α {sub s} =10{sup −3}, required to probe the singlefield slowroll inflationary paradigm. We show that only a veryfuturistic interferometer targeting the dark ages will be capable of measuring the minimal inflationary prediction for β {sub s} . The results of other probes, such as a stochastic background of gravitational waves observable by LIGO, the Lyα forest, and spectral distortions, are shown for comparison. Finally, we study the claims that large values of β {sub s} , if extrapolated to the smallest scales, can produce primordial black holes of tens of solar masses, which we show to be easily testable by the S4 CMB experiment.},
doi = {10.1088/14757516/2017/05/032},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 05,
volume = 2017,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2017},
month = {Mon May 01 00:00:00 EDT 2017}
}

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