skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined With Other Cosmological Probes

Abstract

The first cosmological results from the ESSENCE supernova survey (Wood-Vasey et al. 2007) are extended to a wider range of cosmological models including dynamical dark energy and non-standard cosmological models. We fold in a greater number of external data sets such as the recent Higher-z release of high-redshift supernovae (Riess et al. 2007) as well as several complementary cosmological probes. Model comparison statistics such as the Bayesian and Akaike information criteria are applied to gauge the worth of models. These statistics favor models that give a good fit with fewer parameters. Based on this analysis, the preferred cosmological model is the flat cosmological constant model, where the expansion history of the universe can be adequately described with only one free parameter describing the energy content of the universe. Amongst the more exotic models that provide good fits to the data, we note a preference for models whose best-fit parameters reduce them to the cosmological constant model.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; « less
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
898146
Report Number(s):
SLAC-PUB-12320
astro-ph/0701510; TRN: US200706%%399
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Submitted to Astrophys.J.
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COSMOLOGICAL CONSTANT; COSMOLOGICAL MODELS; PROBES; STATISTICS; SUPERNOVAE; UNIVERSE; Astrophysics,ASTRO

Citation Formats

Davis, Tamara M., Mortsell, E., Sollerman, J., Becker, A.C., Blondin, S., Challis, P., Clocchiatti, A., Filippenko, A.V., Foley, R.J., Garnavich, P.M., Jha, S., Krisciunas, K., Kirshner, R.P., Leibundgut, B., Li, W., Matheson, T., Miknaitis, G., Pignata, G., Rest, A., Riess, A.G., Schmidt, B.P., and /Bohr Inst. /Stockholm U. /Washington U., Seattle, Astron. Dept. /Harvard-Smithsonian Ctr. Astrophys. /Chile U., Catolica /UC, Berkeley, Astron. Dept. /Notre Dame U. /KIPAC, Menlo Park /Texas A-M /European Southern Observ. /NOAO, Tucson /Fermilab /Cerro-Tololo InterAmerican Obs. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Res. Sch. Astron. Astrophys., Weston Creek /Harvard U. /Inst. Astron., Honolulu. Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined With Other Cosmological Probes. United States: N. p., 2007. Web. doi:10.1086/519988.
Davis, Tamara M., Mortsell, E., Sollerman, J., Becker, A.C., Blondin, S., Challis, P., Clocchiatti, A., Filippenko, A.V., Foley, R.J., Garnavich, P.M., Jha, S., Krisciunas, K., Kirshner, R.P., Leibundgut, B., Li, W., Matheson, T., Miknaitis, G., Pignata, G., Rest, A., Riess, A.G., Schmidt, B.P., & /Bohr Inst. /Stockholm U. /Washington U., Seattle, Astron. Dept. /Harvard-Smithsonian Ctr. Astrophys. /Chile U., Catolica /UC, Berkeley, Astron. Dept. /Notre Dame U. /KIPAC, Menlo Park /Texas A-M /European Southern Observ. /NOAO, Tucson /Fermilab /Cerro-Tololo InterAmerican Obs. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Res. Sch. Astron. Astrophys., Weston Creek /Harvard U. /Inst. Astron., Honolulu. Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined With Other Cosmological Probes. United States. doi:10.1086/519988.
Davis, Tamara M., Mortsell, E., Sollerman, J., Becker, A.C., Blondin, S., Challis, P., Clocchiatti, A., Filippenko, A.V., Foley, R.J., Garnavich, P.M., Jha, S., Krisciunas, K., Kirshner, R.P., Leibundgut, B., Li, W., Matheson, T., Miknaitis, G., Pignata, G., Rest, A., Riess, A.G., Schmidt, B.P., and /Bohr Inst. /Stockholm U. /Washington U., Seattle, Astron. Dept. /Harvard-Smithsonian Ctr. Astrophys. /Chile U., Catolica /UC, Berkeley, Astron. Dept. /Notre Dame U. /KIPAC, Menlo Park /Texas A-M /European Southern Observ. /NOAO, Tucson /Fermilab /Cerro-Tololo InterAmerican Obs. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Res. Sch. Astron. Astrophys., Weston Creek /Harvard U. /Inst. Astron., Honolulu. Thu . "Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined With Other Cosmological Probes". United States. doi:10.1086/519988. https://www.osti.gov/servlets/purl/898146.
@article{osti_898146,
title = {Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined With Other Cosmological Probes},
author = {Davis, Tamara M. and Mortsell, E. and Sollerman, J. and Becker, A.C. and Blondin, S. and Challis, P. and Clocchiatti, A. and Filippenko, A.V. and Foley, R.J. and Garnavich, P.M. and Jha, S. and Krisciunas, K. and Kirshner, R.P. and Leibundgut, B. and Li, W. and Matheson, T. and Miknaitis, G. and Pignata, G. and Rest, A. and Riess, A.G. and Schmidt, B.P. and /Bohr Inst. /Stockholm U. /Washington U., Seattle, Astron. Dept. /Harvard-Smithsonian Ctr. Astrophys. /Chile U., Catolica /UC, Berkeley, Astron. Dept. /Notre Dame U. /KIPAC, Menlo Park /Texas A-M /European Southern Observ. /NOAO, Tucson /Fermilab /Cerro-Tololo InterAmerican Obs. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Res. Sch. Astron. Astrophys., Weston Creek /Harvard U. /Inst. Astron., Honolulu},
abstractNote = {The first cosmological results from the ESSENCE supernova survey (Wood-Vasey et al. 2007) are extended to a wider range of cosmological models including dynamical dark energy and non-standard cosmological models. We fold in a greater number of external data sets such as the recent Higher-z release of high-redshift supernovae (Riess et al. 2007) as well as several complementary cosmological probes. Model comparison statistics such as the Bayesian and Akaike information criteria are applied to gauge the worth of models. These statistics favor models that give a good fit with fewer parameters. Based on this analysis, the preferred cosmological model is the flat cosmological constant model, where the expansion history of the universe can be adequately described with only one free parameter describing the energy content of the universe. Amongst the more exotic models that provide good fits to the data, we note a preference for models whose best-fit parameters reduce them to the cosmological constant model.},
doi = {10.1086/519988},
journal = {Submitted to Astrophys.J.},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 25 00:00:00 EST 2007},
month = {Thu Jan 25 00:00:00 EST 2007}
}
  • We investigate the implications for some nonstandard cosmological models using data from the first three years of the Supernova Legacy Survey (SNLS3), assuming a spatially flat universe. A comparison between the constraints from the SNLS3 and those from other SN Ia samples, such as the ESSENCE, Union2, SDSS-II, and Constitution samples, is given and the effects of different light-curve fitters are considered. We find that analyzing SNe Ia with SALT2 or SALT or SiFTO can give consistent results and the tensions between different data sets and different light-curve fitters are obvious for fewer-free-parameters models. At the same time, we alsomore » study the constraints from SNLS3 along with data from the cosmic microwave background and the baryonic acoustic oscillations (CMB/BAO), and the latest Hubble parameter versus redshift (H(z)). Using model selection criteria such as {chi}{sup 2}/dof, goodness of fit, Akaike information criterion, and Bayesian information criterion, we find that, among all the cosmological models considered here ({Lambda}CDM, constant w, varying w, Dvali-Gabadadze-Porrati (DGP), modified polytropic Cardassian, and the generalized Chaplygin gas), the flat DGP is favored by SNLS3 alone. However, when additional CMB/BAO or H(z) constraints are included, this is no longer the case, and the flat {Lambda}CDM becomes preferred.« less
  • We present constraints on the dark energy equation-of-state parameter, w = P/({rho}c{sup 2}), using 60 Type Ia supernovae (SNe Ia) from the ESSENCE supernova survey. We derive a set of constraints on the nature of the dark energy assuming a flat Universe. By including constraints on ({Omega}{sub M}, w) from baryon acoustic oscillations, we obtain a value for a static equation-of-state parameter w = -1.05{sub -0.12}{sup +0.13} (stat 1{sigma}) {+-} 0.13 (sys) and {Omega}{sub M} = 0.274{sub -0.020}{sup +0.033} (stat 1{sigma}) with a best-fit {chi}{sup 2}/DoF of 0.96. These results are consistent with those reported by the Super-Nova Legacy Surveymore » in a similar program measuring supernova distances and redshifts. We evaluate sources of systematic error that afflict supernova observations and present Monte Carlo simulations that explore these effects. Currently, the largest systematic currently with the potential to affect our measurements is the treatment of extinction due to dust in the supernova host galaxies. Combining our set of ESSENCE SNe Ia with the SuperNova Legacy Survey SNe Ia, we obtain a joint constraint of w = -1.07{sub -0.09}{sup +0.09} (stat 1{sigma}) {+-} 0.13 (sys), {Omega}{sub M} = 0.267{sub -0.018}{sup +0.028} (stat 1{sigma}) with a best-fit {chi}{sup 2}/DoF of 0.91. The current SNe Ia data are fully consistent with a cosmological constant.« less
  • We present observational constraints on the nature of dark energy using the Supernova Legacy Survey three-year sample (SNLS3) of Guy et al. and Conley et al. We use the 472 Type Ia supernovae (SNe Ia) in this sample, accounting for recently discovered correlations between SN Ia luminosity and host galaxy properties, and include the effects of all identified systematic uncertainties directly in the cosmological fits. Combining the SNLS3 data with the full WMAP7 power spectrum, the Sloan Digital Sky Survey luminous red galaxy power spectrum, and a prior on the Hubble constant H{sub 0} from SHOES, in a flat universemore » we find {Omega}{sub m} = 0.269 {+-} 0.015 and w = -1.061{sup +0.069}{sub -} 0{sub .068} (where the uncertainties include all statistical and SN Ia systematic errors)-a 6.5% measure of the dark energy equation-of-state parameter w. The statistical and systematic uncertainties are approximately equal, with the systematic uncertainties dominated by the photometric calibration of the SN Ia fluxes-without these calibration effects, systematics contribute only a {approx}2% error in w. When relaxing the assumption of flatness, we find {Omega}{sub m} = 0.271 {+-} 0.015, {Omega}{sub k} = -0.002 {+-} 0.006, and w = -1.069{sup +0.091}{sub -0.092}. Parameterizing the time evolution of w as w(a) = w{sub 0} + w{sub a} (1 - a) gives w{sub 0} = -0.905 {+-} 0.196, w{sub a} = -0.984{sup +1.094}{sub -1.097} in a flat universe. All of our results are consistent with a flat, w = -1 universe. The size of the SNLS3 sample allows various tests to be performed with the SNe segregated according to their light curve and host galaxy properties. We find that the cosmological constraints derived from these different subsamples are consistent. There is evidence that the coefficient, {beta}, relating SN Ia luminosity and color, varies with host parameters at >4{sigma} significance (in addition to the known SN luminosity-host relation); however, this has only a small effect on the cosmological results and is currently a subdominant systematic.« less
  • We review, compare and extend recent studies searching for evidence for a preferred cosmological axis. We start from the Union2 SnIa dataset and use the hemisphere comparison method to search for a preferred axis in the data. We find that the hemisphere of maximum accelerating expansion rate is in the direction (l,b) = (309°{sup +23°}{sub −3°},18°{sup +11°}{sub −10°}) (Ω{sub 0m} = 0.19) while the hemisphere of minimum acceleration is in the opposite direction (l,b) = (129°{sup +23°}{sub −3°},−18°{sup +10°}{sub −11°}) (Ω{sub 0m} = 0.30). The level of anisotropy is described by the normalized difference of the best fit values ofmore » Ω{sub 0m} between the two hemispheres in the context of ΛCDM fits. We find a maximum anisotropy level in the Union2 data of ΔΩ{sub 0mmax} / Ω{sub 0m} = 0.43±0.06. Such a level does not necessarily correspond to statistically significant anisotropy because it is reproduced by about 30% of simulated isotropic data mimicking the best fit Union2 dataset. However, when combined with the axes directions of other cosmological observations (bulk velocity flow axis, three axes of CMB low multipole moments and quasar optical polarization alignment axis), the statistical evidence for a cosmological anisotropy increases dramatically. We estimate the probability that the above independent six axes directions would be so close in the sky to be less than 1%. Thus either the relative coincidence of these six axes is a very large statistical fluctuation or there is an underlying physical or systematic reason that leads to their correlation.« less
  • With a model independent method the expansion history H(z), the deceleration parameter q(z) of the universe and the equation of state w(z) for the dark energy are reconstructed directly from the 192 Sne Ia (type Ia supernovae) data points which are contained in the new ESSENCE (Equation of State: Supernovae Trace Cosmic Expansion) Sne Ia data and the high redshift Sne Ia data. We find that the evolving properties of q(z) and w(z) reconstructed from the 192 Sne Ia data seem to be weaker than those obtained from the Gold set, but stronger than those from the SNLS (Supernova Legacymore » Survey) set. With a combination of the 192 Sne Ia and BAO (Baryonic Acoustic Oscillation) data, a tight constraint on {Omega}{sub m0} is obtained. At the 1{sigma} confidence level {Omega}{sub m0} = 0.278{sub -0.023}{sup +0.024}, which is highly consistent with the values from the Gold + BAO and SNLS + BAO data.« less