Expanding universe

Hot big-bang theory of expanding universe includes an (incorrect) theory of nucleogenesis... 

Albert Einstein is considered the greatest modem physicist because his theories influenced topics in physics ranging from the basis for lasers to the expanding universe. 

The epoch and mode of galaxy formation are not well known, but both quasars and star-forming galaxies are known with redshifts up to about 7, corresponding to an era when the expanding Universe was only 1/8 of its present size, and the emission-line spectra of quasars indicate a large heavy-element abundance (solar or more Hamann Ferland 1999), suggesting prior stellar activity. The first stars, on the other hand, known as Population IIP, would have been devoid of metals whether they differed from normal stars in other basic characteristics, notably their mass distribution, is not known, since no completely metal-free stars have been... 

There is no evidence that Minkowski space is flat on the large scale. The assumption of euclidean Minkowski space could therefore be, and probably is an illusion, like the flat earth. In fact, there is compelling evidence from observed spectroscopic red shifts that space is curved over galactic distances. These red shifts are proportional to distances from the source, precisely as required by a curved space-time[52j. An alternative explanation, in terms of an expanding-universe model that ascribes the red shifts to a Doppler... 

Mosmann TR, Sad S The expanding universe of T-cell subsets Thl, Th2 and more. Immunol Today 1996 17 142-146. 

De Luca, V. and Laflamme, P. 2001. The expanding universe of akaloid biosynthesis. Current Opinion in Plant Biology, 4 225-333. 

Osterbrock DE, Gwinn JA, Brashear RS. Edwin Hubble and the expanding universe. Sci Am 1993 84. 

Earlier, we examined the possibility that life could ultimately be curtailed throughout the Universe by the laws of thermodynamics. Whether this is true or not depends on the validity of certain assumptions (Sect. 6.2). In any case, such a termination would be tens or hundreds of billions of years into the future, if there is an open, forever-expanding Universe. Of closer concern is our Solar System, where the time lines for life are shorter, but still billions of years into the future (Sect. 6.3). It seems a foregone conclusion that life in our Solar System will someday be terminated. 

Although in Minkowski space, this corresponds to energy and momentum conservation, this is no longer the case in an expanding universe. 

So far, we have been able to build a scenario which solves the horizon, flatness and monopole problems. As we already said, this scenario also explains the existence of an almost scale invariant spectrum in the cosmological perturbations. However, the derivation of this crucial result is significantly more involved than the previous one. First because we need to do a careful study of the cosmological perturbation in the context of general relativity and in an expanding universe. Second because we then need to solve these equations in the specific case of inflation. Third, because perturbation theory only tell of the evolution of cosmological perturbations, so that we need to specify the... 

In 10.4,1 will discuss the evolution of density perturbations in an expanding Universe and in 10.5 the plasma oscillations thereby induced. In 10.6 I will introduce that statistical tools to describe the distribution of CMB tem-pertatures on the sky, and in 10.7 how the cosmological parameters influence the distribution of temperatures. Finally, in 10.8 I will briefly review how we actually analyze CMB data and conclude in 10.8. 

All of these effects are included in codes like CMBFAST (Seljak and Zal-darriaga 1996 Zaldarriaga and Seljak, 2000, http //www.cmbfast.org/) and CAMB (Lewis et al., 2000, http //camb.info/) which solve the combined Boltzmann and linearized Einstein equations in an expanding Universe. These codes allow one to calculate the CMB temperature power spectrum for a given model. A sample of spectra for various input cosmological parameters is shown in Figure 10.2. 

WIMPZILLAs Our last example of cold dark matter candidates illustrates a fascinating idea for generating matter in the expanding universe the gravitational creation of matter in an accelerated expansion. This mechanism is analogous to the production of Hawking radiation around a black hole, and of Unruh radiation in an accelerated reference frame. 

Gravitational production of particles is an important phenomenon that is worth describing here. Consider a scalar field (particle) X of mass Mx in the expanding universe. Let r/ be the conformal time and a(r/) the time dependence of the expansion scale factor. Assume for simplicity that the universe is flat. 

Fulling, S. A. 1979. Remarks On Positive Frequency And Hamiltonians In Expanding Universes, Gen. Rel. Grav. 10, 807 Fulling, S. A., 1989. Aspects of Quantum Field Theory in Curved Spacetime (Cambridge CambridgeUniversity Press)... 

Man is. . . related inextricably to all reality, known and unknowable. .. plankton, a shimmering phosphorescence on the sea and the spinning planets and an expanding universe, all bound together by the elastic string of time. It is advisable to look from the tidal pool to the stars and then back to the tide pool again. 

DE LUCA, V., LAFLAMME, P., The expanding universe of alkaloid biosynthesis., Curr. Opin. Plant Biol., 2001,4,225-233. 

The positive value for the change in entropy means that there will be more disorder. An expanding universe and a food fight are sure signs of more disorder. 

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