Test for the cosmological constant with the number count of faint galaxies

Fukugita, M.; Takahara, Fumio; Yamashita, K.; Yoshii, Yuzuru

doi:10.1086/185813

Cited by 101 publications

(76 citation statements)

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“…White et al 1994;Crittenden & Turok 1996), though not as large as it would be for hyperbolic models of corresponding matter densities Ω 0 . Given the recent observational evidence in favour of a flat, cosmological constant dominated universe (Fukugita et al 1990;Fort et al 1997;Chiba & Yoshii 1997;Perlmutter et al 1999), observational motivation for considering the ISW also exists.…”

Section: Introductionmentioning

confidence: 99%

A counterexample to claimed COBE constraints on compact toroidal universe models

Roukema

2000

Class. Quantum Grav.

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It has been suggested that if the Universe satisfies a flat, multiply connected, perturbed FriedmannLemaître model, then cosmic microwave background data from the COBE satellite implies that the minimum size of the injectivity diameter (shortest closed spatial geodesic) must be larger than about two fifths of the horizon diameter. To show that this claim is misleading, a simple T 2 ×R universe model of injectivity diameter a quarter of this size, i.e. a tenth of the horizon diameter, is shown to be consistent with COBE four year observational maps of the cosmic microwave background. This is done using the identified circles principle.

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Section: Introductionmentioning

confidence: 99%

A counterexample to claimed COBE constraints on compact toroidal universe models

Roukema

2000

Class. Quantum Grav.

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“…(iii) Some kinematic measurements of Q10 based upon galaxy counts indicate that 0l0 is close to unity (27,28).…”

Section: Weighing the Universementioning

confidence: 95%

Dark matter: theoretical perspectives.

Turner

1993

Proc. Natl. Acad. Sci. U.S.A.

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I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yetfact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that (i) there are no dark-matter candidates within the "standard model" of particle physics, (ii) there are several compelling candidates within attractive extensions of the standard model of particle physics, and (ii) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for "new physics." The compelling candidates are a very light axion (10-6-10-4 eV), a light neutrino (20-90 eV), and a heavy neutralino (10 GeV-2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos. OverviewOne of the simplest yet most fundamental questions we can ask in cosmology concerns the quantity and composition of the matter in the Universe: What is mass density, QO, expressed as a fraction of the critical density, and what are the contributions of the various constituents-e.g., baryons, photons, and whatever else? [The critical density PCRIT = 3H0/8irG = 1.88h2 x 10-29 g-cm3 = 1.05 x 104 eV-cm3, where Ho = 100h km sec-1 Mpc-1; 1 eV = 1.602 x 10-19 J; 1 megaparsec (Mpc) = 3.09 x 1022 m.] The answer to this question bears upon almost every topic discussed at this colloquium: the expansion age and fate of the Universe; the origin of structure in the Universe and cosmic background radiation (CBR) anisotropies; galactic disks, rotation curves, and morphology; cluster dynamics; gravitational lensing; and the distribution of light and mass. The only thing we know with great precision is the contribution of photons, nZ = 2.49h-2 X 10-4 (assuming Tyo = 2.73 K), and neutrinos, Ql, = 1.70h-2 X 10-4 (assuming all three species are massless); and based on primordial nucleosynthesis, we know the contribution of baryons to within a factor of two, nBh2 = 0.01-0.02 (see, e.g., refs.

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“…When Ω Λ is positive and comparable to Ω, the universe should have gone through a phase of slower expansion in the recent cosmological past, which should be observed as an accumulation of objects at a specific redshift of order unity. In particular, it should be reflected in the observed rate of lensing of high-redshift quasars by foreground galaxies (Fukugita et al 1990). The contours of constant lensing probability in the Ω − Ω Λ plane for z s ∼ 2 happen to almost coincide with the lines Ω − Ω Λ = const.…”

Section: Cosmological Parametersmentioning

confidence: 99%

Cosmological Implications of Large-Scale Flows

Dekel

1997

Galaxy Scaling Relations: Origins, Evolution and Applications

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Cosmological implications of the observed large-scale peculiar velocities are reviewed, alone or combined with redshift surveys and CMB data. The latest version of the POTENT method for reconstructing the underlying three-dimensional velocity and mass-density fields is described. The initial fluctuations and the nature of the dark matter are addressed via statistics such as bulk flow and mass power spectrum. The focus is on constraining the mass density parameter Ω, directly or via the parameter β which involves the unknown relation between galaxies and mass. The acceptable range for Ω is found to be 0.4 − 1.0. The range of β estimates is likely to reflect non-trivial features in the galaxy biasing scheme, such as scale dependence. Similar constraints on Ω and Λ from global measures are summarized.

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Test for the cosmological constant with the number count of faint galaxies

Cited by 101 publications

References 0 publications

A counterexample to claimed COBE constraints on compact toroidal universe models

A counterexample to claimed COBE constraints on compact toroidal universe models

Dark matter: theoretical perspectives.

Cosmological Implications of Large-Scale Flows

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