The lectures that four authors present in this volume investigate core topics related to the accelerated expansion of the Universe. Accelerated expansion occured in the ?36 very early Universe – an exponential expansion in the in ationary period 10 s after the Big Bang. This well-established theoretical concept had rst been p- posed in 1980 by Alan Guth to account for the homogeneity and isotropy of the observable universe, and simultaneously by Alexei Starobinski, and has since then been developed by many authors in great theoretical detail. An accelerated expansion of the late Universe at redshifts z< 1 has been disc- ered in 1998; the expansion is not slowing down under the in uence of gravity, but is instead accelerating due to some uniformly distributed, gravitationally repulsive substance accounting for more than 70% of the mass–energy content of the U- verse, which is now known as dark energy. Its most common interpretation today is given in terms of the so-called CDM model with a cosmological constant .
The lectures that four authors present in this volume investigate core topics related to the accelerated expansion of the Universe.
The first lecture covers the inflationary period in the very early Universe.
The second lecture revolves around the accelerated expansion of the late Universe at redshifts z < 1 due to the enigmatic dark energy that is commonly interpreted as a cosmological constant. The discovery of this accelerated expansion relied on data from type Ia supernovae, so this second lecture is dedicated to the astrophysics of type Ia supernovae and their role in cosmological observations.
The third lecture, which seeks alternative explanations of dark energy, deals with modified gravity models. Such theories presently appear to be the most serious competitors to conventional dark-energy models based on a cosmological constant or its time-dependent counterparts arising from a scalar field
And the fourth lecture discusses currently available statistical methods that are indispensable for the analysis of cosmological data, thus making them necessary prerequisites for many of the results of modern cosmological research
This book is intended to serve as an entry point for graduate students and young researchers into active cosmological research.
