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Non-baryonic matter

Fig. 4.1. Schematic thermal history of the Universe showing some of the major episodes envisaged in the standard model. GUTs is short for grand unification theories and MWB is short for (the last scattering of) the microwave background radiation. The Universe is dominated by radiation and relativistic particles up to a time a little before that of MWB and by matter (including non-baryonic matter) thereafter, with dark energy eventually taking over. Fig. 4.1. Schematic thermal history of the Universe showing some of the major episodes envisaged in the standard model. GUTs is short for grand unification theories and MWB is short for (the last scattering of) the microwave background radiation. The Universe is dominated by radiation and relativistic particles up to a time a little before that of MWB and by matter (including non-baryonic matter) thereafter, with dark energy eventually taking over.
Basic models of massive non-baryonic matter (of neutralino type) suggest a hierarchical formation of structures. They work on the hypothesis that... [Pg.107]

Nothing is known about the nature of the energy component, which goes under the name of dark energy. Of the matter component, less than 2% is luminous, and no more than 20% is made of ordinary matter like protons, neutrons, and electrons. The rest of the matter component, more than 80% of the matter, is of an unknown form which we call non-baryonic. Finding the nature of non-baryonic matter is referred to as the non-baryonic dark matter problem. [Pg.279]

Inflation also distorts the mass budget of the universe so badly that less than 1% of the total mass appears visible, but this is the total mass that neatly balances the large-number coincidences of the anthropic principle. The excess must therefore be non-baryonic matter, for which there is no evidence. At the same time, the equal mass of antibaryons, implied by CPT symmetry, is declared non-existent. Antileptons are simply ignored. [Pg.222]

One took three different gauge theories, supplied them with some free parameters, added an ad hoc Higgs mechanism to make it work, and the result seems to function properly. It is not known exactly why those three symmetries create the three interactions although the U(l) symmetry is clearly related to the electromagnetic charge, the SU(2) to the weak isospin, and SU(3) to the three colors. It is not clear why there are exactly three fermion families and how the fermions of a family are related to each other (apart from the sum of their charges). It is not known why there is no antimatter in the Universe, and there is the deep mystery of dark matter astronomical observations indicate that about 90% of the mass of the Universe is invisible, probably non-baryonic matter that cannot be explained within the framework of the Standard Model (Amsler et al. 2008). [Pg.472]

The other kind of dark matter must be non-baryonic (NDM) and is thought to consist of some kind of particles envisaged in extensions of the Standard Model ... [Pg.2]

The existence of dark matter (either baryonic or non-baryonic) is inferred from its gravitational effects on galactic rotation curves, the velocity dispersions and hydrostatic equilibrium of hot (X-ray) gas in clusters and groups of galaxies, gravitational lensing and departures from the smooth Hubble flow described by Eq. (4.1). This dark matter resides at least partly in the halos of galaxies such as our... [Pg.148]

In the standard case there are four variables to be calculated the total system mass M (not counting non-baryonic dark matter), the mass of gas g, the mass existing in the form of stars (including compact remnants) s and the abundance Z of the element(s) of interest, assuming certain initial conditions and laws governing the SFR and flows of material into and out of the system. [Pg.243]

The fact that the Sun is in the plasma state means that it has the flexibility of a gas. This flexibility in turn ensures its longevity. Indeed, the size of the particles making it up, i.e. separate nuclei and electrons, is much less than the mean distance separating them, and this allows us to identify it with a gas. (Non-baryonic dark matter, with no electrical properties, cannot be ionised. There is no such thing as a dark matter plasma.)... [Pg.80]

Only those scraps of matter more concentrated than the medium in which they have accumulated can foretell the emergence of cosmic forms. And these embryonic galaxies can only be random concentrations of the undifferentiated magma comprising photons, baryons and non-baryonic particles. [Pg.107]

However, according to the latest estimates, the fraction of our Galaxy s dark halo that could be explained by baryonic matter (low-luminosity stars and non-luminous compact, massive objects) cannot exceed 20%. These estimates are based on the effect such objects would have on the hght from stars in the Magellanic Clouds. It is concluded that the halo of our Galaxy, and probably that of other spirals of this type, is not principally made up of ordinary, atomic matter. [Pg.199]

This method is based on the measurement of the baryonic fraction in clusters, consisting mainly of the hot gas seen in X-rays. The X-ray image of a cluster allows one to measure the mass of this X-ray gas. The knowledge of the X-ray temperature allows one to estimate the total mass Mit. It possible therefore to estimate the baryon fraction in clusters (the contribution of stars, around 1% for h = 0.5 is often neglected to first order) assuming that the remaining dark matter is non-baryonic, which can be related to Do ... [Pg.68]

In the late seventies, the history of the early Universe was described with the help of the hot Big-Bang scenario the universe originated from an initial singularity and had then expanded, being filled by radiation and subsequently by non relativistic matter (baryon and Dark Matter). [Pg.101]

Already in 1970s suggestions have been made that some sort of non-baryonic elementary particles may serve as candidates for dark matter particles. Gunn et al. (1978) considered heavy stable neutral leptons as possible candidates for dark matter particles, however in a later study Tremaine Gunn (1979)... [Pg.252]

The new paradigm wins when its theoretical foundation is established. In the case of the dark matter this was done by Blumenthal et al. (1984) with the non-baryonic cold dark matter hypothesis. Also the need for non-baryonic dark matter was clarified otherwise the main constituents of the universe -galaxies, clusters and filamentary superclusters - cannot form. [Pg.257]

To conclude we can say that the story of dark matter is not over yet - we still do not know of what non-baryonic particles the dark matter is made of. [Pg.258]

Figure 16.1. The concordance cosmology and the need for non-baryonic dark matter. Current cosmological measurements of the matter density fim and energy density Qa give the value marked with a cross at fim 0.27, Qa — 0.73. The baryon density does not exceed 0.05 (black vertical band). The rest of the matter is non-baryonic. (Figure adapted from Verde et al.(2002).)... Figure 16.1. The concordance cosmology and the need for non-baryonic dark matter. Current cosmological measurements of the matter density fim and energy density Qa give the value marked with a cross at fim 0.27, Qa — 0.73. The baryon density does not exceed 0.05 (black vertical band). The rest of the matter is non-baryonic. (Figure adapted from Verde et al.(2002).)...
A new kind of elementary particle has been the dominant (exclusive ) candidate for non-baryonic dark matter. [Pg.281]

The three active neutrinos are our only known particle candidates for non-baryonic dark matter. Since they fail to be cold dark matter, we are lead to consider hypothetical particles. [Pg.285]

We need another non-baryonic candidate for cold dark matter. [Pg.288]


See other pages where Non-baryonic matter is mentioned: [Pg.303]    [Pg.20]    [Pg.86]    [Pg.243]    [Pg.190]    [Pg.218]    [Pg.218]    [Pg.303]    [Pg.20]    [Pg.86]    [Pg.243]    [Pg.190]    [Pg.218]    [Pg.218]    [Pg.331]    [Pg.120]    [Pg.149]    [Pg.481]    [Pg.197]    [Pg.85]    [Pg.242]    [Pg.253]    [Pg.279]    [Pg.279]    [Pg.279]    [Pg.280]    [Pg.281]    [Pg.281]    [Pg.281]    [Pg.281]    [Pg.283]    [Pg.285]    [Pg.287]    [Pg.289]    [Pg.291]    [Pg.293]    [Pg.295]   
See also in sourсe #XX -- [ Pg.176 , Pg.218 , Pg.222 , Pg.303 ]




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Baryon

Matter baryonic

Non-baryonic

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