The subject matter in this book covers the theory and observations relating to the earliest epochs of our evolving Universe, from its singular origin to just beyond the epoch of recombination: the first half million years. This is a fundamental period of the Universe's lifetime, and the period from which the key parameters describing it can be determined. As our understanding of the Universe grew, and new observations were found to rule out the simplest models, new physical entities and concepts had to be introduced to ensure consistency between theory and observation. The subsequent period, from recombination to the present epoch, is the era during which stellar and galactic physics takes place, and is not covered in this volume.

Precision Cosmology is a teaching book and a technical reference book which aims to provide a clear and understandable description of the applied mathematics and physics required to establish the high level of precision which can now be achieved for the study of the Universe – Precision Cosmology. It details the background and mathematical tools needed to enable a student embarking on advanced studies and research to understand what others have done and published.

This book is also an experiment in presentation. The printed text is accompanied by extensive online supplements, which provide a high level of didactic mathematical material too extensive to be included in the main text. These supplements are freely available for download and are intended as a source of teaching material for both teachers and students across a range of topics in physics, mathematics and statistics. They are suitable for all levels of university study, from undergraduate to postdoctoral research. The online supplements and other support material are available from

www.BernardJones.net/PrecisionCosmology.html

Figures in the text marked cc are available on this website and are free for use under the terms of the CC-BY-SA Creative Commons License. Exercises and slides for teaching purposes are also to be found on this site.

In this way, much of the book should be accessible to physics and mathematics undergraduates who have had courses in mechanics, electromagnetism and special relativity. The aim is to take the student beyond this basic knowledge, right up to the level of being able to follow and understand research papers, and thus to understand today's cosmology in its proper context as a branch of physics.