Inflation, structure formation and dark matter

This paper provides a review of the variants of dark matter (CDM, HDM) which are thought to be fundamental components of the universe and their role in origin and evolution of structures.

In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenges-developing a detailed understanding of the formation of structure in the Universe and identifying the constituents of the ubiquitous dark matter. I then discuss the motivations for-and the fundamentals of-inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses t...

Cold + Hot Dark Matter (CHDM) is perhaps the best theory of cosmic structure formation {\it if} the cosmological matter density is near critical (i.e., $\Omega_0 \approx 1$) and {\it if} the expansion rate is not too large (i.e. $h \equiv H_0/(100 \kmsMpc) \lsim 0.6$). I discuss CHDM together with its chief competitor among CDM variants, low-$\Omega_0$ CDM with a cosmological constant (\lcdm). \lcdm\ with $\Omega_0 \sim 0.3$ has the possible virtue of allowing a higher expans...

We briefly review some selected topics gravitating around large scale structures. We derive from inflation the evolution of dark matter perturbations. The stress is put on the non-linear regime of structures formation, with a particular emphasis on relativistic effects, the Effective Field Theory approach, the role of dark energy and the possibility of inhomogeneous universes.

We use linear and quasi-linear perturbation theory to analyse cold dark matter models of structure formation in spatially flat models with a cosmological constant. Both a tilted spectrum of density perturbations and a significant gravitational wave contribution to the microwave anisotropy are allowed as possibilities. We provide normalizations of the models to microwave anisotropies, as given by the four-year {\it COBE} observations, and show how all the normalization informa...

The standard model of cosmology is based on the hot Big Bang theory and the inflationary paradigm. Recent precise observations of the temperature and polarization anisotropies in the cosmic microwave background and the matter distribution in large scale structures like galaxies and clusters confirm the general paradigm and put severe constrains on variations of this simple idea. In this essay I will discuss the epistemological foundations of such a paradigm and speculate on i...

We review the current standard model for the evolution of the Universe from an early inflationary epoch to the complex hierarchy of structure seen today. We summarize and provide key references for the following topics: observations of the expanding Universe; the hot early Universe and nucleosynthesis; theory and observations of the cosmic microwave background; Big Bang cosmology; inflation; dark matter and dark energy; theory of structure formation; the cold dark matter mode...

Massive neutrinos were the first proposed, and remain the most natural, particle candidate for the dark matter. In the absence of firm laboratory evidence for neutrino mass, considerations of the formation of large scale structure in the universe provide a sensitive, albeit indirect, probe of this possibility. Observations of galaxy clustering and large angle anisotropy in the cosmic microwave background have been interpreted as requiring that neutrinos provide about 20% of t...

A short introduction to structure formation is given, followed by a discussion of the possible characteristics of the initial perturbations assuming a generic inflationary origin. Observational data related to large-scale structure and the cosmic microwave background radiation is then used in an attempt to constrain the characteristics of such perturbations. Future directions are also explored. The possibility of direct detection of a stochastic gravitational wave backgroun...

The currently standard theory of cosmic structure formation posits that the present-day clumpy appearance of the universe developed through gravitational amplification of the matter density fluctuations that are generated in the very early universe. The energy content of the univese and the basic statistics of the initial density field have been determined with a reasonable accuracy from recent observations of the cosmic microwave background, large-scale structure, and distan...