Matter Content of the Universe  

In General > s.a. astronomy; cosmological parameters; early-universe cosmology, baryogenesis and nucleosynthesis; matter distribution.
* 1995: The dogma is Ωb ≈ 0.05, Ωdm ≈ 0.95, Ωcc = 0.
* 1998: M Turner & D Schramm predict 5% ordinary matter, based on deuterium abundance.
* 1999: "Matter" consists of ordinary matter/radiation (Ω ≈ 0.2), dark matter, and dark energy (possibly a cosmological constant).
* 2000: Cold dark matter from new cmb data; Favored values Ωm ≈ 0.4 ± 0.1, Ωb = 0.02 h–2, 0.001 < Ων < 0.1, Ωcc ≈ 0.7.
* 2001: New DASI and Boomerang cmb data; Favored values Ωb = 0.05, Ωdm = 0.30, Ωde = 0.65 (p < 0).
* 2002: 2dF galaxy redshift survey and cmb, Ωm = 1 – Ωcc = 0.30; Using KamLAND data, Ων ≤ 0.070 h–2.
* 2003: WMAP data give Ωb = 0.04, Ωdm = 0.23, Ωde = 0.73; SDSS data, Ωb = 0.05, Ωdm = 0.25, Ωde = 0.70.
* 2003: The ΛCDM model provides the best fit to the data, with Ωtot = 1.02 ± 0.02.
* 2013: GRBs as standard candles give Ωm = 0.30, Ωde = 0.70; WMAP 5-year data Ωm = 0.27, Ωde = 0.73; Planck mission Ωm = 0.317, Ωde = 0.683.
* 2015: Planck mission data give Ωm = 0.308 ± 0.012.
* Critical density: At the present time, ρcrit = 6 H atoms/m3 = 10–26 kg/m3; Notice that Ωcc = Λ c2/3H02.
* Entropy: The entropy of the universe is low but increasing.
@ General references: Melott PRP(90); Persic & Salucci MNRAS(92)ap/05 [baryons]; Bahcall ap/96 [large-scale structure]; White ap/96-conf [large z]; Dolgov NPPS(02)ap, hp/02-proc [antimatter]; Krauss & Scherrer PRD(07)ap [radiation cannot become dominant again]; Holder et al ApJ(10)-a0907 [baryon-dark matter ratio fluctuations]; Ferreira & Starkmann Sci(09)nov-a0911 [dark fields vs modified gravity].
@ Density: Coles & Ellis Nat(94)aug, 97; Bahcall & Fan PNAS(98)ap; Krauss AIP(98)hp [cosmological constant]; Bahcall PS(00)ap/99-conf [galaxy clusters]; Roos & Harun-or-Rashid ap/00, ap/00 [flatness]; Turner ApJL(02)ap/01; Schindler ap/01-in [Ωm]; Waterhouse & Zibin a0804 [variation of Ω]; Lee JCAP(14)-a1307 [from large-scale structure].

Types of Matter > s.a. dark matter; inflationary scenarios; topological defects.
* Components: Ordinary "baryonic" matter, dark matter, "dark energy" (possibly a cosmological constant).
* 2008: Recent experiments, including PAMELA, ATIC, WMAP, and EGRET, have revealed unusually high electron-positron production in the cosmos, more so than can be explained by mechanisms such as supernova explosions or cosmic-ray collisions; This discrepancy is leading some researchers to speculate that dark matter may play a part [@ news pt(08)nov].
@ Reviews: Dine ht/01-conf; Durrer ap/02-proc; Fukugita & Peebles ApJ(04)ap [energy inventory].
@ General references: Melia A&A(15)-a1411 [cosmic equation of state]; Clifton a1509-MG14 [is modeling the matter as dust adequate?]; Neeleman et al ApJ-a1601 [HI].
@ Repulsive matter: Cornish & Starkman ap/98; > s.a. dark energy.
@ Mirror matter: Foot PLB(99)ap [stars?], PLB(99)ap [planets?]; Mohapatra & Teplitz PLB(99)ap [MACHOs?]; Foot & Mitra APP(03)ap/02 [Solar System]; Foot & Silagadze IJMPD(05) [supernovas and GRBs]; Ciarcelluti IJMPD(05), IJMPD(05).
@ Other diffuse background: Henry ApJL(99)ap; Lagache et al ASS(99)ap [sub-mm]; Zhao et al PLB(09) [free-streaming gas in radiation-dominated era]; Dwek & Krennrich APP(13)-a1209, news sn(13)aug [extragalactic background light]; Dado & Dar a1411 [common origin for gamma-ray and neutrino backgrounds, GRBs from jets in type Ic supernovae]; Cooray a1602-RSOS [extragalactic background over 20 decades in wavelength]; > s.a. astronomy at various wavelengths [cosmic radio and infrared backgrounds]; cosmic microwave background; gamma rays; gravitons; neutrinos.

blue bullet And fundamental physics: see antimatter; electroweak theory; quantum fields in curved spacetime; structure of matter.
blue bullet Phenomenology: see astronomical phenomena; magnetism in astrophysics and cosmology; observational cosmology [including matter and radiation].

Observational Missions
* Past: COBE (Cosmic Background Explorer), launched in 1989; It reported the first anisotropy in 1992.
* Present and future: WMAP (Wilkinson Microwave Anisotropy Probe) launched in 2001, reported results in 2003, 2006, 2008 (5-year results), 2011 (7-year results); ESA's Planck satellite launched in 2009.


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