Basics of Cosmology

Observatoire de Paris, 61 Av.de I Observatoire, 75014 Paris, France Monique.Signore obspm.fr 

Observatoire Midi-Pyrenees, CNRS 14, Av. Ed. Belin, 31 400 Toulouse, France Alain.Blanchard ast.obs-mip.fr 

We will begin by briefly reviewing the General Cosmological Framework in which the following lectures will fit the Hot Big Bang  

This model, which ancestor is the Lemai tre Primeval atom, is but a mere 40 years old and provides a description of some other observations like, in particular, the abundances of light elements. 

The paper is organized as follows in section 2, we briefly review the geometry and dynamics of the Universe and then give the Einstein-Friedman-Lemaitre (hereafter EEL) equations section 3 introduces some important quantities needed for observations in section 4, we rapidly present some solutions of the EEL equations, i.e. some cosmological models in section 5, the Standard Big Bang Nucleosynthesis Model is described while section 6 shows a statement of observations of primordial abundances in section 7, we confront the predictions of the Standard Big Bang Nucleosynthesis (hereafter SBBN) model to the observations of the primordial abundances a brief conclusion is 

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Psychology is the science that strives to understand, measure, and modify our behavior what we do, what we say, what we think, and what we feel. At its most basic level, behavior describes how we manipulate and respond to our environment. It is the ultimate output of the nervous system. Its domain ranges across the entire universe of human activities from simple reflexes to the creation of cosmological theories. Toxicology, however, at least in the formal sense, recognized the crucial role of behavioral neuroscience only recently. Perhaps behavior seemed somewhat exotic compared to the study and traditional endpoints of death and tissue damage. However, step back from the brink that these endpoints represent and toxicology swiftly becomes a more complex and subtle enterprise. 

Systems that do not tend to approach a maximum of entropy might be basically of interest in cosmology, if the big bang stops to bang. However, we should annotate that at the time when Clausius formulated the second law, nothing was known about the big bang. 

The gravitational field is described in general relativity by the set of equations (4.11). The right hand side depends on the description of matter in the system of interest and the corresponding solution consists of finding that form of the fundamental tensor that satisfies (4.11). The first successful solution of cosmological interest, obtained by Schwarzschild, is text-book material, described in detail by Adler et al. (1965). The time-independent spherically symmetric line element is of particular importance as a model of the basic one-body problem of classical astronomy. This element, of the form ... 

It was the first evolutionary formulation of cosmology. This was a revolutionary statement as the existence of irreversible processes (and therefore of entropy) conflicts with the time-reversible view of dynamics. Of course, classical dynamics has been superseded by quantum theory and relatively. But this conflict remains because in both quantum theory and relativity the basic dynamical laws are time-reversible. 

The main goal of the Planck instrument is to improve the accuracy of the measurement of the cosmic microwave background (CMB), in order to extract cosmological parameters that remain poorly constrained after the results of WMAP (Wilkinson microwave anisotropy probe) and of the best ground-based experiments. The basic idea of HFI-Planck is to use all the information contained in the CMB radiation, i.e. to perform a radiometric measurement limited by the quantum fluctuations of the CMB radiation itself. In these conditions, the accuracy is only limited by the number of detectors and by the duration of the observation. 

We simply do not have any really good theories or models of psi today in the sense of comprehensive or really detailed understandings of basic phenomena. What general theories we have so far in parapsychology tend to be too general, too cosmological in scope, and they are more philosophical positions than precise formulations that could lead to predictions whereby we could test their validity. We desperately need smaller-scale theories that are testable. We are starting to get them, but we do not have many yet. 

Around about 1980, William Tifft, a radio astronomer at the University of Arizona in Tucson, had the wild idea that, perhaps, the cosmological redshifts of galaxies had preferences for multiples of some basic unit. Subsequently, he looked and made two claims [1,2] ... 

In Chap. 1, we introduced the book with a quote from Albert Einstein (Schilpp 1949), which read in part that classical thermodynamics... is the only physical theory of universal content concerning which I am convinced that, within the framework of the applicability of its basic concepts, it will never be overthrown. An important qualification to this statement is the phrase within the framework of the applicability of its basic concepts. The laws of thermodynamics are based on laboratory-scale experiments. To assume that such laws are applicable to the Universe is a big assumption. However, we have no evidence yet that contradicts this assumption on the scales of problems relevant to life. Moreover, there remain vast cosmological questions with no answers and definitely no understanding of implications even if we knew the answers. For instance, does the proton have a very long but finite radioactive half-life Does the neutrino have a very small but finite mass Is the Universe opened or closed with respect to expansion and gravitational contraction Also, the Universe may not be isolated with respect to matter/energy or it could be isolated and cyclical. 

Therefore, the most precise verification of the basic cosmological framework now comes from the observations of the spectrum and of the anisotropies of the CMB. 

The nature of the DM basic constituents is still unknown. Among the viable competitors for having a cosmologically relevant DM species (see, e.g., Gon-dolo in these Proceedings), the leading candidate is the lightest supersymmetric... 

Of course, any cosmology must account for facts such as the observed expansion of the universe. In the face of this incontrovertible observation, steady state theorists had to find a way to keep matter from thinning out as the expansion occurred and to maintain a constant density of matter over time. To do this they made a bold and unfounded basic assumption they assumed that hydrogen atoms are continuously created throughout all of space. To match the observed expansion and to maintain a constant density of matter, about one hydrogen atom must appear in each and every cubic meter of space every 300,000 years. 

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