Cosmology and Nongalactic Astrophysics · arXiv:1305.0313 v2 · submitted 1 May 2013
Primordial Non-Gaussianity Estimation using 21 cm Tomography from the Epoch of Reionization
The paper says
“We find that an optimum, multi-frequency observation by SKA can achieve ΔfNL ∼ 3 (comparable to recent Planck CMB limits), while a cosmic-variance-limited array of this size like Omniscope can even detect ΔfNL ∼ 0.2.”
from the abstract · picked out as the main claim by a classifier
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The paper
Abstract
Measuring the small primordial nonGaussianity (PNG) predicted by cosmic inflation theories may help diagnose them. The detectability of PNG by its imprint on the 21cm power spectrum from the epoch of reionization is reassessed here in terms of fNL, the local nonlinearity parameter. We find that an optimum, multi-frequency observation by SKA can achieve ΔfNL ∼ 3 (comparable to recent Planck CMB limits), while a cosmic-variance-limited array of this size like Omniscope can even detect ΔfNL ∼ 0.2. This substantially revises the methods and results of previous work.
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abstract compiled · 2026-09-23 · no language-model review
How the main claim is stated: asserted 1.00
What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.12 · human participants 0.02 · controlled comparison 0.10 · randomized assignment 0.01 · states quantitative result 0.98 · compares with prior results 0.91 · mentions code or data availability 0.02
The abstract, sentence by sentence
This table labels the abstract only (arXiv listing abstract v2). The number is the probability the classifier gave the label.
| Sentence | Role | The authors' own work | States the main conclusion | Strength |
|---|---|---|---|---|
| Measuring the small primordial nonGaussianity (PNG) predicted by cosmic inflation theories may help diagnose them. | background 1.00 | 0.05 | 0.03 | hedged possibility 1.00 |
| The detectability of PNG by its imprint on the 21cm power spectrum from the epoch of reionization is reassessed here in terms of $f_{NL}$, the local nonlinearity parameter. | contribution 0.87 | 0.68 | 0.05 | asserted 0.84 |
| We find that an optimum, multi-frequency observation by SKA can achieve $\Delta f_{NL} \sim 3$ (comparable to recent Planck CMB limits), while a cosmic-variance-limited array of this size like Omniscope can even detect $\Delta f_{NL} \sim 0.2$. | result 1.00 | 0.95 | 0.87 | asserted 1.00 |
| This substantially revises the methods and results of previous work. | contribution 0.50 | 0.45 | 0.07 | asserted 1.00 |
What kind of paper the classifier reports this is: theoretical result 0.62 · evidence from simulation or computation 0.84
What was examined, and what was not
Sources read
- arXiv listing abstract v2
Not examined
- full text
- figures and tables
- references and citing sentences
- relations to other papers
Levels run
- P abstract
Not run
- S sections
- T body sentences
- C citations
- R cross-paper relations
How the labels were made
Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 3,703 input tokens, $0.0002 reported.
Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. This record as JSON
Cited by 5 Pith papers
Reviewed papers on Pith that cite this one. The full citation record
- The Epoch of Reionization Window: II. Statistical Methods for Foreground Wedge Reduction astro-ph.CO · Apr 2014
- Curvature constraints from Large Scale Structure astro-ph.CO · Mar 2016
- Constraints on primordial non-Gaussianity from 800,000 photometric quasars astro-ph.CO · May 2014
- Cosmology on Ultralarge Scales with Intensity Mapping of the Neutral Hydrogen 21 cm Emission: Limits on Primordial Non-Gaussianity astro-ph.CO · May 2013
- Inflation and Early Dark Energy with a Stage II Hydrogen Intensity Mapping Experiment astro-ph.CO · Oct 2018
How the literature uses it
10 arXiv papers cite this in 10 sentences
Papers citing it · 7 sentences without a confident label
Cites it as background 3 papers
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While non-Gaussianity from $21$cm has been studied in the dark ages [ref] and the epoch of reionization [ref] , our focus in this section will be on the low-redshift universe [ref] , specifically constraints coming from the proposed Stage ii experiment in the redshift range $2≤z ≤6$.
Inflation and Early Dark Energy with a Stage II Hydrogen Intensity Mapping Experiment · Primordial non-Gaussianity · 0.81
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The ability to constrain the first two of these parameters has been investigated in several works by looking at both the CMB [ref] and the large-scale structure (LSS) of the universe [ref] , or a combination of the two [ref] .
Curvature constraints from Large Scale Structure · Introduction · 0.96
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Further input on (primordial and otherwise) non-Gaussian characterizations of inflationary models is expected to originate from Large Scale Structure sources (see, e.g., [ref] ) and possibly from future CMB polarization experiments (see, e.g., [ref] , [ref] and [ref] ) Another important probe might well be 21cm cosmology [ref] .
On the Trispectrum of Galileon Inflation · Conclusions · 0.84
What it cites · 2 sentences without a confident label
Uses data or values from 2 papers
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Recent measurement of the CMB anisotropy bispectrum by Planck has placed the most stringent constraint so far, $f_NL^local = 2.7 ±5.8$ [ref] .
Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity · Introduction · 0.95
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Recent cosmic microwave background (CMB) temperature anisotropy measurements find $n_s ≈0.96$ [ref] , so $f_NL^local≈0.016$.
Planck 2013 results. XVI. Cosmological parameters · Introduction · 0.99
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