Related papers: Cosmology at the Millennium
One of the main challenges in cosmology is to quantify how small density fluctuations at the recombination epoch z around 1000 evolved into the galaxies and the large-scale structure we observe in the universe today. This thesis discusses…
Present-day elliptical, spiral and irregular galaxies are large systems made of stars, gas and dark matter. Their properties result from a variety of physical processes that have occurred during the nearly fourteen billion years since the…
Every society has a story rooted in its most ancient traditions, of how the earth and sky originated. Most of these stories attribute the origin of all things to a Creator - whether God, Element or Idea. We first recall that in the Western…
In the first two years of operation JWST has delivered key new insights into the formation and evolution of galaxies in the early Universe. By combining imaging with spectroscopy, we discovered and characterised the first generation of…
The current standard model of cosmology assumes that the majority of matter in the Universe is made of dark matter, and that the latter is fundamentally different from ordinary matter. Dark matter can in principle explain the rotation of…
A better understanding of the formation of large-scale structure in the Universe is arguably the most pressing question in cosmology. The most compelling and promising theoretical paradigm, Inflation + Cold Dark Matter, holds that the…
Observations made using large ground-based and space-borne telescopes have probed cosmic history all the way from the present-day to a time when the Universe was less than a tenth of its present age. Earlier on lies the remaining frontier,…
An introductory account is given of the modern understanding of the physics of the early Universe. Particular emphasis is placed on the paradigm of cosmological inflation, which postulates a period of accelerated expansion during the…
How do galaxies form and evolve? This is one of the most puzzling questions in astronomy. Galaxy assembly takes place throughout the entire history of the Universe, but our understanding of it is hampered by the unfortunate fact that we can…
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…
Galaxy formation is at the heart of our understanding of cosmic evolution. Although there is a consensus that galaxies emerged from the expanding matter background by gravitational instability of primordial fluctuations, a number of…
The expansion of our universe, when followed backward in time, implies that it emerged from a phase of huge density, the big bang. These stages are so extreme that classical general relativity combined with matter theories is not able to…
We discuss a cosmological model where the universe shrinks rather than expands during the radiation and matter dominated periods. Instead, the Planck mass and all particle masses grow exponentially, with the size of atoms shrinking…
Understanding the behavior of the universe at large depends critically on insights about the smallest units of matter and their fundamental interactions. Inflationary cosmology is a highly successful framework for exploring these…
In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of…
Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both…
Over the last decades, observations with increasing quality have revolutionized our understanding of the general properties of the Universe. Questions posed for millenia by mankind about the origin, evolution and structure of the cosmos…
The standard big bang cosmological model and the history of the early universe according to the grand unified theories of strong, weak and electromagnetic interactions are summarized. The shortcomings of big bang are discussed together with…
The standard theory of cosmic structure formation posits that the present-day rich structure of the Universe developed through gravitational amplification of tiny matter density fluctuations generated in its very early history. Recent…
The large scale structure of the present Universe is determined by the growth of dark matter density fluctuations and by the dynamical action of dark energy and dark matter. While much progress has been made in recent years in constraining…