SIGN, a WIMP Detector Based on High Pressure Gaseous Neon

White, J. T.; Gao, J.; Maxin, James A.; Miller, J.M.; Salinas, Gerardo; Wang, H.

doi:10.1007/3-540-26373-x_22

Cited by 11 publications

(14 citation statements)

References 7 publications

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“…Chiba & Yoshii (1998) emphasized this point, reporting an analysis with E/S0 luminosity functions that yielded a best-fit mass density in a flat cosmology of Ω flat M = 0.3 +0.2 −0.1 , in agreement with our SN Ia results. Several papers have emphasized that upcoming balloon and satellite studies of the Cosmic Background Radiation (CBR) should provide a good measurement of the sum of the energy densities, Ω M + Ω Λ , and thus provide almost orthogonal information to the supernova measurements (White 1998;Tegmark et al 1998). In particular, the position of the first acoustic peak in the CBR power spectrum is sensitive to this combination of the cosmological parameters.…”

Section: Comparison With Complementary Constraintsmentioning

confidence: 99%

“…Such an entity can lead to a different expansion history than the cosmological constant does, because it can have a different relation ("equation of state") between its density ρ and pressure p than that of the cosmological constant, p Λ /ρ Λ = −1. We can obtain constraints on this equation-of-state ratio, w ≡ p/ρ, and check for consistency with alternative theories (including the cosmological constant with w = −1) by fitting the alternative expansion histories to data; White (1998) has discussed such constraints from earlier supernovae and CBR results. In Figure 10, we update these constraints for our current supernova dataset, for the simplest case of a flat universe and an equation of state that does not vary in time (cf.…”

Section: Cosmological Implicationsmentioning

confidence: 99%

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Measurements of Ω and Λ from 42 High‐Redshift Supernovae

Perlmutter

Aldering

Goldhaber

et al. 1999

ApJ

15,941

292

9,869

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We report measurements of the mass density, Ω M , and cosmological-constant energy density, Ω Λ , of the universe based on the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology Project. The magnitude-redshift data for these supernovae, at redshifts between 0.18 and 0.83, are fit jointly with a set of supernovae from the Calán/Tololo Supernova Survey, at redshifts below 0.1, to yield values for the cosmological parameters. All supernova peak magnitudes are standardized using a SN Ia lightcurve width-luminosity relation. The measurement yields a joint probability distribution of the cosmological parameters that is approximated by the relation 0.8 Ω M − 0.6 Ω Λ ≈ −0.2 ± 0.1 in the region of interest (Ω M ∼ < 1.5). For a flat (Ω M + Ω Λ = 1) cosmology we find Ω flat M = 0.28 +0.09 −0.08 (1σ statistical) +0.05 −0.04 (identified systematics). The data are strongly inconsistent with a Λ = 0 flat cosmology, the simplest inflationary universe model. An open, Λ = 0 cosmology also does not fit the data well: the data indicate that the cosmological constant is non-zero and positive, with a confidence of P(Λ > 0) = 99%, including the identified systematic uncertainties. The best-fit age of the universe relative to the Hubble time is t flat 0 = 14.9 +1.4 −1.1 (0.63/h) Gyr for a flat cosmology. The size of our sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We find no significant differences in either the host reddening distribution or Malmquist bias between the low-redshift Calán/Tololo sample and our high-redshift sample. Excluding those few supernovae which are outliers in color excess or fit residual does not significantly change the results. The conclusions are also robust whether or not a width-luminosity relation is used to standardize the supernova peak magnitudes. We discuss, and constrain where possible, hypothetical alternatives to a cosmological constant.

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Section: Comparison With Complementary Constraintsmentioning

confidence: 99%

Section: Cosmological Implicationsmentioning

confidence: 99%

Measurements of Ω and Λ from 42 High‐Redshift Supernovae

Perlmutter

Aldering

Goldhaber

et al. 1999

ApJ

15,941

292

9,869

View full text Add to dashboard Cite

show abstract

“…2 shows the leading-order prediction for the χ 2 isocurvature model (Peebles 1997, 1998a, 1998b, Antoniadis, etal. 1997, Linde & Mukhanov 1997, White 1998 with the APM-like spectrum. In this model, the initial density field is the square of a Gaussian random field, and the leading-order 3-point function is simply ζ = 2[2ξ(x 12 )ξ(x 13 )ξ(x 23 )] 1/2 .…”

Section: Introductionmentioning

confidence: 99%

The Projected Three-Point Correlation Function: Theory and Observations

Frieman

Gaztañaga

1999

The Astrophysical Journal

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We report results for the angular three-point galaxy correlation function in the APM survey and compare them with theoretical expectations. For the first time, these measurements extend to sufficiently large scales to probe the weakly non-linear regime. On large scales, the results are in good agreement with the predictions of non-linear cosmological perturbation theory, for a model with initially Gaussian fluctuations and linear power spectrum P (k) consistent with that inferred from the APM survey. These results reinforce the conclusion that large-scale structure is driven by non-linear gravitational instability and that APM galaxies are relatively unbiased tracers of the mass on large scales; they also provide stringent constraints upon models with non-Gaussian initial conditions and strongly exclude the standard cold dark matter model.

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“…(M. White has independently noted similar conditions for degeneracy for constant w models. 22 ) Our results are based on full numerical codes which include the fluctuations in Q and the gravitational lensing distortion. 23 Our computations confirm that the above conditions are a good approximation to the degeneracy curves.…”

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confidence: 99%

Resolving the cosmological missing energy problem

et al. 1999

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Some form of missing energy may account for the difference between the observed cosmic matter density and the critical density. Two leading candidates are a cosmological constant and quintessence (a time-varying, inhomogenous component with negative pressure). We show that an ideal, full-sky cosmic background anisotropy experiment may not be able to distinguish the two and, due to this ambiguity, may not determine the matter density or Hubble constant. We further show that degeneracy may remain even after considering classical cosmological tests and measurements of large scale structure.This paper looks ahead a few years to a time when highly precise, full-sky maps of the cosmic microwave background (CMB) anisotropy become available from satellite experiments such as the NASA Microwave Anisotropy Probe (MAP) and the ESA Planck mission. The goal is to determine if measurements of the anisotropy by itself or combined with other cosmological constraints can resolve between competing models for the "missing energy" of the universe. The missing energy problem arises because inflationary cosmology and some current microwave anisotropy measurements suggest that the universe is flat at the same that a growing number of observations indicate that the matter density (baryonic and nonbaryonic) is below the critical density (Ω m < 1). These two trends can be reconciled if there is another contribution to the energy density of the universe besides matter. One candidate for the missing energy is a vacuum density or cosmological constant (Λ).1 A second candidate is quintessence, a time-varying, spatially inhomogeneous component with negative pressure.2 Both models fit all current observations well. 1, 3If current observational trends continue, determining the nature of the missing energy will emerge as one of cosmology's most important challenges. The issue must be decided in order to understand the energy composition of the universe. Also, as shown below, ambiguity concerning the missing energy leads to large uncertainties in two key parameters: Ω m and h (the Hubble constant in units of 100 km sec −1 Mpc −1 ). In this Letter, we show that, despite extraordinary advances in measurements of the CMB anisotropy and large-scale structure anticipated in the near future, the missing energy problem and, consequently Ω m and h, may remain unresolved in some circumstances.The key differences between quintessence and vacuum density are: (1) quintessence has an equation-of-state w (equal to the ratio of pressure to energy density) greater than −1, whereas vacuum density has w precisely equal to −1; (2) the energy density for quintessence varies with time whereas the vacuum density is constant; and (3), quintessence is spatially inhomogeneous and can cluster gravitationally, whereas vacuum density remains spatially uniform. The first two properties result in different predictions for the expansion rate. The third property results in a direct imprint of quintessence fluctuations on the CMB and large scale structure.For the purposes of thi...

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SIGN, a WIMP Detector Based on High Pressure Gaseous Neon

Cited by 11 publications

References 7 publications

Measurements of Ω and Λ from 42 High‐Redshift Supernovae

Measurements of Ω and Λ from 42 High‐Redshift Supernovae

The Projected Three-Point Correlation Function: Theory and Observations

Resolving the cosmological missing energy problem

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