Reading the thread…
Reading the thread…
From the 2000 MAXIMA and BOOMERANG measurements through WMAP (2003–2012) and SDSS galaxy clustering, this thread used complementary geometric and growth-rate constraints to measure dark energy density and equation of state independently of supernovae. BAO measurements added a standard ruler, progressively reducing uncertainties to percent-level precision.
20 papers, in the order the idea moved · each quote is the paper’s own definition, and each is marked to say whether we found it word for word in the paper (verified), could not find it (inferred), or have not re-checked it against the paper’s text as it now stands
The paper lists vacuum energy as one of the cosmological parameters that its fast CMB calculation method is designed to accurately handle across the full parameter space.
“These include models with varying amount of dark matter, baryonic matter, Hubble constant, vacuum energy, neutrino mass, shape of initial spectrum of perturbations, reionization and tensor modes.”◌ not checked against the paper’s text as it now stands
The paper identifies that the integrated Sachs-Wolfe contribution to the CMB source term becomes especially important in low matter-density (vacuum-energy-dominated) universes because the gravitational potential decays over time in such models.
“It is especially important if matter-radiation equality occurs close to the recombination or in Ω_ matter 1 models. In both cases gravitational potential decays with time, which leads to an enhancement of anisotropies on large angular scales.”◌ not checked against the paper’s text as it now stands
“These include models with varying amount of dark matter, baryonic matter, Hubble constant, vacuum energy, neutrino mass, shape of initial spectrum of perturbations, reionization and tensor modes.”✓ verified · A Line-of-Sight Integration Approach to …, 1996
The paper included the cosmological constant Ω_Λ as one of the free parameters varied in its grid of cold dark matter models used to fit the CMB power spectrum.
“the cosmological constant, Ω_Λ (0-1); the Hubble constant, h (0.5-0.8); the baryon density, h^2Ω_b (0.013-0.025), the primordial scalar spectral index, ns (0.8-1.3); and the overall normalization A (freeparameter) of the primordial density fluctuation power spectrum.”◌ not checked against the paper’s text as it now stands
It mapped out the allowed region in the Ω_m-Ω_Λ plane consistent with the measured peak location, showing this region is narrow and elongated along the flat-universe line.
“In Figure 3 we mark with black dots the region of the Ω_m-Ω_Λ plane where some combination of the remaining four parameters within the ranges defined by our model space gives a power spectrum consistent with our 95% confidence interval for ℓ_peak. This region is quite narrow and elongated along the "flat Universe" line Ω_m+ Ω_Λ = 1.”◌ not checked against the paper’s text as it now stands
The paper derived a 95% confidence interval for the total density Ω_0 = Ω_m+Ω_Λ, effectively constraining the combined contribution of matter and dark energy (cosmological constant) to the universe's density.
“Marginalizing over all the other parameters, we found the following 95% confidence interval for Ω_0 = Ω_m+Ω_Λ: 0.88< Ω_0 <1.12.”
The paper finds that the best-fit cosmological model to the MAXIMA-1 power spectrum requires a non-zero cosmological constant (dark energy).
“The best-fit model has a total energy density close to unity and a non-zero cosmological constant.”◌ not checked against the paper’s text as it now stands
The paper explicitly compares the measured power spectrum to a ΛCDM model that includes a cosmological constant term.
“The top panel of Figure […] shows the maximum likelihood power spectrum, an inflationary adiabatic model that best fits the MAXIMA-1 and COBE/DMR power spectra, and a ΛCDM model.”◌ not checked against the paper’s text as it now stands
The paper quantifies the goodness-of-fit (χ²) of the ΛCDM model, which includes dark energy, against the data.
“The χ^2 for the best fit and for the ΛCDM models are 41 and 50, respectively, using all 38 data points.”◌ not checked against the paper’s text as it now stands
“The best-fit model has a total energy density close to unity and a non-zero cosmological constant.”
The paper reports that the measured CMB power spectrum is consistent with low spatial curvature, Λ-dominated cold dark matter models, implicitly supporting the presence of a dark energy component.
“The spectrum is consistent with low spatial curvature, Λ-dominated adiabatic CDM models.”◌ not checked against the paper’s text as it now stands
The paper states that its results, combined with other cosmological measurements, place significant constraints on the total density parameter Ω_tot, which is directly tied to the amount of dark energy needed for a flat universe.
“These results, in concert with other types of cosmological measurements and theoretical models, significantly constrain the values of Ω_ tot, Ω_bh^2, Ω_ch^2 and n_s.”◌ not checked against the paper’s text as it now stands
The paper notes that the position of the fundamental acoustic peak provides evidence for a low curvature universe, a result consistent with a substantial dark energy contribution as predicted by many inflationary models.
“Data from a variety of experiments […] including a small fraction of the data from the BOOMERANG 1998/1999 Long Duration Ballooning (BOOM/LDB) campaign ( […]; B00 hereafter) clearly show this feature and provide strong evidence for a low curvature universe, a generic prediction of many inflation models.”
The paper introduces the dark energy equation of state parameter w as a base cosmological parameter and constrains it using MCMC analysis.
“and allow for an effective constant equation of state parameter[ Many quintessence models can be described accurately by a constant effective equation of state parameter […]. We compute the perturbations by using a quintessence potential V(ϕ) with V_,ϕ = -3/2(1-w) H ϕ̇ and V_,ϕϕ = -3/2(1-w)[ Ḣ - 3/2(1+w) H^2 ] that gives a constant equation of state. ] w≡ p/ρ for the dark energy, and assume that -1 ≤ w < 0.”◌ not checked against the paper’s text as it now stands
The paper derives the dark energy density parameter Ω_Λ from the flatness constraint given the curvature and matter densities.
“We derive Ω_Λ, the ratio of the critical density in the form of dark energy, from the constraint Ω_K + Ω_Λ + Ω_m = 1 (where Ω_m≡Ω_c + Ω_b is the total matter density in units of the critical density).”◌ not checked against the paper’s text as it now stands
The paper finds joint constraints on matter and dark energy densities consistent with the popular 0.3/0.7 concordance model using combined CMB, HST, 2dF, supernova and BBN data.
“The matter and dark energy densities are spot on the popular 0.3, 0.7 model, although with error bars of 0.05 at 68 per cent confidence.”
The paper's best-fit cosmological model derived from WMAP CMB data finds that the flat universe is composed of 73% dark energy.
“This flat universe model is composed of 4.4% baryons, 22% dark matter and 73% dark energy.”◌ not checked against the paper’s text as it now stands
The paper places a constraint on the dark energy equation of state parameter using the CMB and other cosmological data.
“The dark energy equation of state is limited to w < -0.78 (95%).”◌ not checked against the paper’s text as it now stands
“This flat universe model is composed of 4.4% baryons, 22% dark matter and 73% dark energy. The dark energy equation of state is limited to w < -0.78 (95%).”✓ verified · First‐Year <i>Wilkinson Microwave Anisot…, 2003
The paper places an observational constraint on the equation of state of dark energy using WMAP data combined with other astronomical data.
“the equation of state of the dark energy, w < -0.78 (95% confidence limit assuming w ≥ -1.).”◌ not checked against the paper’s text as it now stands
The paper identifies dark energy as one of the fundamental components of the standard cosmological model alongside radiation, baryons, and cold dark matter.
“In this model the Universe is spatially flat, homogeneous and isotropic on large scales, composed of radiation, ordinary matter (electrons, protons, neutrons and neutrinos), non-baryonic cold dark matter, and dark energy.”◌ not checked against the paper’s text as it now stands
The paper shows that models with a dark energy equation of state very different from a cosmological constant require a much lower Hubble constant to fit the WMAP data, testing the viability of alternative dark energy models.
“As we will show in 6, models with equation of state for the dark energy very different from a cosmological constant (i.e., w=-1) only fit the WMAP data if the Hubble constant is much smaller than the Hubble Key Project value.”
The paper assumed a flat universe with a cosmological constant equation of state for dark energy as a prior in its inflationary parameter analysis.
“The priors on the model are: a flat universe, a cosmological constant equation of state for the dark energy, and a restriction of τ<0.3.”◌ not checked against the paper’s text as it now stands
“The priors on the model are: a flat universe, a cosmological constant equation of state for the dark energy, and a restriction of τ<0.3.”✓ verified · First‐Year <i>Wilkinson Microwave Anisot…, 2003
The paper treats dark energy density and its equation of state as explicit free cosmological parameters constrained jointly with WMAP and SDSS data.
“Ω_Λ Dark energy density Not optional MCMC w Dark energy equation of state Worth testing MCMC p_Λ/ρ_Λ (approximated as constant)”◌ not checked against the paper’s text as it now stands
The paper shows that adding SDSS large-scale structure data substantially tightens the WMAP-only constraints on the dark energy density Ω_Λ (equivalently Ω_m).
“on the matter density from Ω_m≈ 0.25± 0.10 to Ω_m≈ 0.30± 0.04 (1σ)”◌ not checked against the paper’s text as it now stands
The paper demonstrates that dropping strong priors on curvature and dark energy equation of state weakens constraints, and that combining SDSS with SN Ia data helps recover tight constraints even when the dark energy equation of state is allowed to vary.
“SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state.”◌ not checked against the paper’s text as it now stands
The paper places a significant constraint on the dark energy equation of state using WMAP combined with Supernova Legacy Survey data in a flat universe.
“In a flat universe, the combination of WMAP and the Supernova Legacy Survey (SNLS) data yields a significant constraint on the equation of state of the dark energy, w = -0.967^+ 0.073_- 0.072.”◌ not checked against the paper’s text as it now stands
The paper shows that even without assuming flatness, combining WMAP with large-scale structure and supernova data still yields a strong constraint on the dark energy equation of state.
“Even if we do not include the prior that the universe is flat, by combining WMAP, large-scale structure and supernova data, we can still put a strong constraint on the dark energy equation of state, w = -1.08±0.12.”◌ not checked against the paper’s text as it now stands
The paper derives the dark energy density parameter Ω_Λ by combining WMAP three-year data with the HST key project constraint on H0.
“The combination of WMAP three year data plus the HST key project constraint on H_0 implies Ω_k = -0.014±0.017 and Ω_Λ= 0.716±0.055.”◌ not checked against the paper’s text as it now stands
The paper measures baryon acoustic oscillations to determine a distance measure independent of dark energy assumptions, providing a robust cross-check.
“Baryon oscillations are clearly detected and provide a robust measurement of the comoving distance to the median survey redshift z=0.35 independent of curvature and dark energy properties.”◌ not checked against the paper’s text as it now stands
The paper uses the LRG power spectrum combined with WMAP data to constrain the dark energy equation of state parameter w.
“Assuming Ω_ tot=1, the equation of state parameter is constrained to w=-0.94± 0.09, indicating the potential for more ambitious future LRG measurements to provide precision tests of the nature of dark energy.”◌ not checked against the paper’s text as it now stands
The paper argues that future, more ambitious LRG surveys could provide precision tests of the nature of dark energy.
“indicating the potential for more ambitious future LRG measurements to provide precision tests of the nature of dark energy.”◌ not checked against the paper’s text as it now stands
The paper measures the distance-redshift relation ratio between two redshifts using BAO and compares it with predictions from ΛCDM cosmologies constrained by supernova dark energy data.
“The recovered ratio is roughly consistent with that predicted by the higher redshift SNLS supernovae data for ΛCDM cosmologies, but does require slightly stronger cosmological acceleration at low redshift.”◌ not checked against the paper’s text as it now stands
The paper derives constraints on the dark energy equation of state parameter w by combining BAO measurements with supernova and CMB data.
“If we force the cosmological model to be flat with constant w, then we find =0.249±0.018 and w=-1.004±0.089 after combining with the SNLS data, and including the WMAP measurement of the apparent acoustic horizon angle in the CMB.”◌ not checked against the paper’s text as it now stands
The paper finds that the BAO data require slightly stronger cosmological acceleration at low redshift, relevant to dark energy behavior.
“The recovered ratio is roughly consistent with that predicted by the higher redshift SNLS supernovae data for ΛCDM cosmologies, but does require slightly stronger cosmological acceleration at low redshift.”◌ not checked against the paper’s text as it now stands
The paper places tight, simultaneous constraints on a constant dark energy equation of state and spatial curvature using WMAP data combined with BAO and SN.
“We obtain tight, simultaneous limits on the (constant) equation of state of dark energy and the spatial curvature of the universe: -0.14<1+w<0.12 and -0.0179<Ω_k<0.0081.”◌ not checked against the paper’s text as it now stands
The paper tests time-dependent (evolving) dark energy equation of state models and constrains its present-day value.
“We test a time-dependent w with a present value constrained as -0.33<1+w_0<0.21 (95% CL).”◌ not checked against the paper’s text as it now stands
The paper provides a set of distance priors specifically to enable testing of various dark energy models including those with spatial curvature.
“We provide a set of “distance priors,” to test a variety of dark energy models with spatial curvature.”◌ not checked against the paper’s text as it now stands
The paper measures the dark energy density parameter as a key output of the 6-parameter ΛCDM fit.
The paper derives a five-year WMAP-only measurement of the dark energy density parameter within the ΛCDM model.
“Ω_Λ= 0.742±0.030,”◌ not checked against the paper’s text as it now stands
The paper explicitly defines dark energy parameters used in its analysis, including the density and equation of state.
“Ω_Λ Dark energy density, with w=-1 unless stated”◌ not checked against the paper’s text as it now stands
The paper tests an extended cosmological model allowing a constant dark energy equation of state parameter w rather than assuming a cosmological constant.
“They also include models with a curved geometry Ω_k, a constant dark energy equation of state w, and those with massive neutrinos”◌ not checked against the paper’s text as it now stands
The paper shows that its neutrino mass constraint is robust to variations in the dark energy equation of state.
“The current -only limit on the sum of the neutrino masses is ∑m_ν< 1.3, which is robust, to within 10%, to a varying tensor amplitude, running spectral index or dark energy equation of state.”
The paper reports a measured dark energy density parameter using WMAP combined with SN and BAO data.
“Ω_bh^2 = 0.02267^+ 0.00058_- 0.00059, Ω_ch^2 = 0.1131±0.0034, Ω_Λ= 0.726±0.015,”◌ not checked against the paper’s text as it now stands
The paper derives tight simultaneous constraints on the dark energy equation of state parameter and spatial curvature.
“We obtain tight, simultaneous limits on the (constant) dark energy equation of state and the spatial curvature of the universe: -0.14<1+w<0.12 and -0.0179<Ω_k<0.0081.”◌ not checked against the paper’s text as it now stands
The paper combines CMB acoustic scale measurements with galaxy BAO measurements to constrain the geometry of the universe and the properties of dark energy, concluding the universe is dominated by dark energy consistent with a cosmological constant.
“When combined, these standard rulers accurately measure the geometry of the universe and the properties of the dark energy. These data require a nearly flat universe dominated by dark energy consistent with a cosmological constant.”◌ not checked against the paper’s text as it now stands
The paper uses BAO distance measurements combined with supernova and CMB data to constrain the equation of state of dark energy, finding w consistent with -1.
“Combining these data sets with the full WMAP5 likelihood constraints provides tight constraints on both Ω_k=-0.006±0.008 and w=-0.97±0.10 for a constant dark energy equation of state.”◌ not checked against the paper’s text as it now stands
The paper shows that its cosmological constraints from BAO and supernovae are independent of the behavior of dark energy outside the redshift range probed.
“This result is independent of the behaviour of dark energy at redshifts greater than those probed by the BAO and supernova measurements.”◌ not checked against the paper’s text as it now stands
The paper frames BAO as a key tool for probing the cosmic expansion history to address the nature of dark energy.
the tool’s reading · not checked against the paper’s text as it now standsThe paper explicitly parameterizes dark energy density and equation of state as cosmological parameters used in its analysis.
“For flat ΛCDM models these are the Hubble constant H_0, the densities of baryonic matter Ω_b, cold dark matter Ω_c, all matter Ω_m, and dark energy Ω_Λ. Going beyond this simple class of models, we use the equation of state of the dark energy w, the curvature energy density Ω_k and total energy density Ω_ tot.”
The paper derives a constraint on a constant dark energy equation of state parameter w using WMAP data combined with BAO and H0 measurements, without high-redshift supernovae.
“The limit on a constant dark energy equation of state parameter from +BAO+H_0, without high-redshift Type Ia supernovae, is w = -1.10±0.14 (68% CL).”◌ not checked against the paper’s text as it now stands
The paper explicitly explores the nature of dark energy in a dedicated section and notes that supernova data are needed to improve limits on dark energy properties.
“the supernova data are needed to improve limits on properties of dark energy (see Table […] and Section […]), and”◌ not checked against the paper’s text as it now stands
The paper provides a summary table of 68% limits on dark energy properties, including constant w and time-varying w0, wa parameters, derived from combinations of WMAP with BAO, H0, time-delay distance, and supernova data.
“Summary of the 68% limits on dark energy properties from combined with other data sets”◌ not checked against the paper’s text as it now stands
The paper reports a precise nine-year WMAP-derived value for the dark energy density parameter when combined with other cosmological data.
“the matter and energy densities, Ω_bh^2, Ω_ch^2, and Ω_Λ, are each determined to a precision of ∼1.5%.”◌ not checked against the paper’s text as it now stands
The paper places new constraints on the dark energy equation of state parameters using WMAP plus external data such as supernovae.
“Section […] presents constraints on parameters beyond the standard model, such as the tensor-to-scalar ratio, the running spectral index, the amplitude of isocurvature modes, the number of relativistic species, the mass of neutrinos, spatial curvature, the equation of state parameters of dark energy, and cosmological birefringence.”◌ not checked against the paper’s text as it now stands
The paper notes that systematic errors in Type Ia supernova data directly increase the uncertainty on the dark energy equation-of-state parameter w.
“Including the term C_ sys has a significant effect: it increases the error on the dark energy equation of state, σ_w from 0.05 to 0.08 in a flat universe.”◌ not checked against the paper’s text as it now stands
The paper measured the dark-energy equation of state parameter w by combining supernova data with CMB constraints for a flat universe.
“When combined with CMB constraints, we measure a constant dark-energy equation of state parameter w=-1.018 ± 0.057(stat+sys) for a flat universe. Adding BAO distance measurements gives similar constraints: w=-1.027 ± 0.055.”◌ not checked against the paper’s text as it now stands
The authors claim their supernova sample yields the tightest constraints yet obtained on dark energy properties.
“Our supernova measurements provide the most stringent constraints to date on the nature of dark energy.”◌ not checked against the paper’s text as it now stands
The paper combines SNe Ia with additional astrophysical probes such as CMB and BAO to break parameter degeneracies and constrain more generic dark energy models.
“Section […] uses additional astrophysical probes in combination with SNe Ia to break degeneracies and constrain dark energy in more generic models. In particular, we include precise measurements of the cosmic microwave background (CMB) and baryon acoustic oscillations (BAO).”◌ not checked against the paper’s text as it now stands
The paper's new distance measurement fills a gap in the BAO distance ladder and significantly improves constraints on dark energy properties.
“This “fills the gap” in BAO distance ladder between previously measured local and higher redshift measurements, and affords significant improvement in constraining the properties of dark energy.”◌ not checked against the paper’s text as it now stands
Combining this measurement with other BAO data yields a 15 per cent improvement in determining the dark energy equation of state and H0.
“Combining our measurement with other BAO measurements from BOSS and 6dFGS galaxy samples provides a 15 per cent improvement in the determination of the equation of state of dark energy and the value of the Hubble parameter at z=0 (H_0).”◌ not checked against the paper’s text as it now stands
The paper emphasizes that probing dark energy requires measurements at multiple redshifts, especially lower redshifts where dark energy effects are more pronounced.
“the MGS samples an independent cosmic volume and a lower redshift range, which is important when studying properties of dark energy since its effects are more pronounced at lower redshifts.”◌ not checked against the paper’s text as it now stands
One thread of the map, each claim pinned to the paper’s own words. A chatbot gives you the canon; this carries the papers in between, in order, with the evidence attached.
“the cosmological constant, Ω_Λ (0-1);”✓ verified · A flat Universe from high-resolution map…, 2000
“Parameters explored include those describing energy densities, including the total energy density Ω_tot, the vacuum energy density Ω_Λ, and the physical densities of baryons and cold dark matter, Ω_b h^2 and Ω_c h^2 respectively.”✓ verified · A Measurement by BOOMERANG of Multiple P…, 2001
The paper notes that supernova constraints on dark energy in the literature often assume a cosmological constant, and instead uses the full supernova likelihood to allow for general dark energy equations of state.
“As a simple example, the Supernova Cosmology Project has made available constraints in Ω_m-Ω_Λ space, which could only be used if the dark energy is a cosmological constant. Fortunately the full supernova data are available, which we use (described below).”◌ not checked against the paper’s text as it now stands
“Our results include constraints on the neutrino mass (m_ν 0.3 eV), equation of state of the dark energy, and the tensor amplitude, as well as demonstrating the effect of additional parameters on the base parameter constraints.”✓ verified · Cosmological parameters from CMB and oth…, 2002
The paper parameterizes dark energy properties using an effective equation of state and examines dark energy models as part of testing extensions to the basic cosmological model.
“We examine non-flat models, dark energy models in which the properties of the dark energy are parameterized by an effective equation of state, and models with gravity waves.”◌ not checked against the paper’s text as it now stands
“In this model the Universe is spatially flat, homogeneous and isotropic on large scales, composed of radiation, ordinary matter (electrons, protons, neutrons and neutrinos), non-baryonic cold dark matter, and dark energy.”✓ verified · First‐Year <i>Wilkinson Microwave Anisot…, 2003
The paper reports a measured value for the dark energy equation of state parameter w using WMAP data with a prior including SN Ia information.
“w -1 -1 -1 -1 -0.72^+ 0.34_- 0.27 -1 -1”◌ not checked against the paper’s text as it now stands
“negligible neutrino masses (f_ν=0) and dark energy corresponding to a pure cosmological constant (w=-1).”✓ verified · Cosmological parameters from SDSS and WM…, 2003
The paper formally parameterizes dark energy equation of state w as part of its cosmological model and defines it in terms of pressure and density of dark energy.
“w Dark energy equation of state w= p_DE/ρ_DE”◌ not checked against the paper’s text as it now stands
“In a flat universe, the combination of WMAP and the Supernova Legacy Survey (SNLS) data yields a significant constraint on the equation of state of the dark energy, w = -0.967^+ 0.073_- 0.072.”✓ verified · Three‐Year<i>Wilkinson Microwave Anisotr…, 2006
The paper improves constraints on spatial curvature within the ΛCDM framework, which is relevant to inferring dark energy properties.
“Within the ΛCDM framework, our power spectrum measurement improves the evidence for spatial flatness, sharpening the curvature constraint Ω_ tot=1.05± 0.05 from WMAP alone to Ω_ tot=1.003± 0.010.”◌ not checked against the paper’s text as it now stands
“Baryon oscillations are clearly detected and provide a robust measurement of the comoving distance to the median survey redshift z=0.35 independent of curvature and dark energy properties.”✓ verified · Cosmological constraints from the SDSS l…, 2006
“If we force the cosmological model to be flat with constant w, then we find =0.249±0.018 and w=-1.004±0.089 after combining with the SNLS data, and including the WMAP measurement of the apparent acoustic horizon angle in the CMB.”✓ verified · Measuring the Baryon Acoustic Oscillatio…, 2007
“Ω_Λ= 0.726±0.015,”◌ not checked against the paper’s text as it now stands
“We also constrain models of dark energy via its equation of state, parity-violating interaction, and neutrino properties such as mass and the number of species.”✓ verified · FIVE-YEAR<i>WILKINSON MICROWAVE ANISOTRO…, 2008
“w Dark energy equation of state, w= p_DE/ρ_DE”✓ verified · FIVE-YEAR<i>WILKINSON MICROWAVE ANISOTRO…, 2008
The paper shows that even allowing for curvature and a free dark energy equation of state, the combination of WMAP and BAO data still determines the Hubble constant precisely.
“Even when allowing curvature (Ω_0 1) and a free dark energy equation of state (w -1), the acoustic data determine the Hubble constant to within 3%.”◌ not checked against the paper’s text as it now stands
“We obtain tight, simultaneous limits on the (constant) dark energy equation of state and the spatial curvature of the universe:”✓ verified · FIVE-YEAR <i>WILKINSON MICROWAVE ANISOTR…, 2008
““What is the nature of dark energy?” is one of the current key questions in physical science.”✓ verified · Baryon acoustic oscillations in the Sloa…, 2009
The paper reports constraints on dark energy equation-of-state evolution parameters w0 and wa using combinations of WMAP with H0, BAO, time-delay distance, and supernova data.
“Ω_k=0 w_0 -0.83± 0.16 -0.93± 0.13 -0.93± 0.12 w_a -0.80^+0.84_-0.83 -0.41^+0.72_-0.71 -0.38^+0.66_-0.65”◌ not checked against the paper’s text as it now stands
“The limit on a constant dark energy equation of state parameter from +BAO+H_0, without high-redshift Type Ia supernovae, is w = -1.10±0.14 (68% CL).”✓ verified · SEVEN-YEAR<i>WILKINSON MICROWAVE ANISOTR…, 2010
The paper restricts its use of supernova data specifically to constrain models examining the dark energy equation of state, given the standard ΛCDM (cosmological constant) model's consistency with the data.
“Hence we restrict our use of supernova data in this paper to the subset of models that examine the dark energy equation of state.”◌ not checked against the paper’s text as it now stands
“Despite its notable success at describing all current cosmological data sets, the standard model raises many questions: what is the nature of dark matter and dark energy?”✓ verified · NINE-YEAR <i>WILKINSON MICROWAVE ANISOTR…, 2012
The paper frames dark energy as the unknown cause of cosmic acceleration that alternative theories like dynamical dark energy or modified gravity attempt to explain.
“The reason for the acceleration remains unknown, and the term “dark energy” is used to describe the phenomenon. Understanding the nature of dark energy is currently one of the major goals of fundamental physics, and this drives a large experimental effort in observational cosmology. While a cosmological constant may be the simplest explanation for the accelerating expansion, alternatives such as dynamical dark energy or modified gravity (see, e.g., […] for a recent review) can be tested through their effects in either the late-time expansion history or the growth of structures in the universe.”◌ not checked against the paper’s text as it now stands
“The reason for the acceleration remains unknown, and the term “dark energy” is used to describe the phenomenon.”✓ verified · Improved cosmological constraints from a…, 2014
The paper situates its measurement within the broader effort to understand the observed cosmic acceleration attributed to dark energy by constraining its equation-of-state through BAO.
“Robust measurements of the cosmological expansion rate are required to understand its observed acceleration at low redshift (see […] for early detections and […] for review of observational probes). If the acceleration is driven by an unknown energy-density component, then these measurements will constrain its equation-of-state.”◌ not checked against the paper’s text as it now stands
“This "fills the gap" in BAO distance ladder between previously measured local and higher redshift measurements, and affords significant improvement in constraining the properties of dark energy.”○ inferred · The clustering of the SDSS DR7 main Gala…, 2014