Astrophysics · arXiv:0711.3180 v2 · submitted 20 Nov 2007
How strong is the evidence for accelerated expansion?
The paper says
“Nevertheless, in a spatially flat universe there is at least a 5 sigma evidence for acceleration which drops to 1.8 sigma in an open universe.”
from the abstract · picked out as the main claim by a classifier
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The paper
Abstract
We test the present expansion of the universe using supernova type Ia data without making any assumptions about the matter and energy content of the universe or about the parameterization of the deceleration parameter. We assume the cosmological principle to apply in a strict sense. The result strongly depends on the data set, the light-curve fitting method and the calibration of the absolute magnitude used for the test, indicating strong systematic errors. Nevertheless, in a spatially flat universe there is at least a 5 sigma evidence for acceleration which drops to 1.8 sigma in an open universe.
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. No sentence in this record was written by a model.
abstract compiled · 2026-09-23 · no language-model review
How the main claim is stated: asserted 0.99
What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.96 · human participants 0.02 · controlled comparison 0.06 · randomized assignment 0.01 · states quantitative result 0.98 · compares with prior results 0.14 · 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 |
|---|---|---|---|---|
| We test the present expansion of the universe using supernova type Ia data without making any assumptions about the matter and energy content of the universe or about the parameterization of the deceleration parameter. | method 0.73 | 0.95 | 0.05 | unclear 0.58 |
| We assume the cosmological principle to apply in a strict sense. | method 0.93 | 0.69 | 0.02 | asserted 0.95 |
| The result strongly depends on the data set, the light-curve fitting method and the calibration of the absolute magnitude used for the test, indicating strong systematic errors. | limitation 0.94 | 0.82 | 0.10 | hedged possibility 0.75 |
| Nevertheless, in a spatially flat universe there is at least a 5 sigma evidence for acceleration which drops to 1.8 sigma in an open universe. | result 1.00 | 0.90 | 0.78 | asserted 0.99 |
What kind of paper the classifier reports this is: empirical study 0.99 · evidence from analysis of existing data 0.99
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, 3,591 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 1 Pith paper
Reviewed papers on Pith that cite this one. The full citation record
- Evaluating backreaction with the peak model of structure formation astro-ph · Jan 2008
How the literature uses it
10 arXiv papers cite this in 24 sentences
Papers citing it · 12 sentences without a confident label
Builds on it 1 paper
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We modified our model-independent test of accelerated expansion presented in [ref] in such a way that systematics due to calibrations are avoided.
Model- and calibration-independent test of cosmic acceleration · Conclusion · 0.85
Uses its method or tool 2 papers
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Our analysis is based on the estimator proposed in [ref] and revisited recently in Ref. [ref] .
Is the Hubble diagram of quasars in tension with concordance cosmology? · Evidence for acceleration in Hubble diagram · 1.00
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The null hypothesis proposed in [ref] is that the universe has never expanded in an accelerated way i.e., $q(z)>0 ∀ z$.
{\it Gauging} the cosmic acceleration with recent type Ia supernovae data sets · A model-independent estimator for cosmic acceleration · 0.83
Uses its data or values 1 paper
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For our test in [ref] , we adopted the values of $M$ and $H_0$ given by Riess et al. [ref] and Sandage et al. [ref] .
Model- and calibration-independent test of cosmic acceleration · Calibration-dependent test · 0.91
Compares with it 1 paper
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Comparing to the results obtained in Refs. [ref] the recent catalogues present even more robust evidence favoring acceleration.
{\it Gauging} the cosmic acceleration with recent type Ia supernovae data sets · Single and Averaged SN analysis with actual UNION2.1 data · 0.92
Cites it as support 1 paper
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Indeed, considerable amount of scatter with unidentified cause has been observed e.g. in the magnitude-redshift relations of the type Ia supernovae and importantly, especially at low redshifts [ref] ; for detailed analysis of scatter in HKP data, see [ref] .
Dark energy as a mirage · Discussion of the fits · 0.96
Cites it as background 1 paper
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Indeed, in units where $8πG_N=1$, but explicitly retaining the speed of light $c$, we have[Note that we are now specifically assuming Friedmann dynamics for the universe, one is thus explicitly stepping outside the “cosmographic” or “cosmokinetic” framework of [ref] . ] [equation] [equation] [equation] The classical energy conditions of general relativity, to the extent that one believes that they are a useful guide [ref] , allow one to deduce physical constraints on the behaviour of matter fields in strong gravitational fields or cosmological geometries.
Cosmodynamics: Energy conditions, Hubble bounds, density bounds, time and distance bounds · Basic formulae · 0.84
What it cites · 10 sentences without a confident label
Uses the method or tool of 1 paper
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This problem can be solved by reparameterizing redshift [ref] .
The Hubble series: Convergence properties and redshift variables · Introduction · 0.82
Cites as support 1 paper
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This effect of averaging can also mimic curvature effects [ref] and thus strongly influence the reconstruction of the dark energy equation of state, as has been shown in [ref] .
Is the Dynamics of Tracking Dark Energy Detectable? · Conclusion · 0.96
Challenges and discussion
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