The nature and essence of Dark Matter and Dark Energy have become the central issue in modern cosmology over the past years. This extensive volume, an outgrowth of a topical and tutorial summer school, has been set up with the aim of constituting an advanced-level, multi-authored textbook which meets the needs of both postgraduate students and young researchers in the fields of modern cosmology and astrophysics.

Dark Matter: The Missing Matter of the Universe as Seen by Astroparticle Physics and Astrophysics.- Particle Physics Approach to Dark Matter.- LSP as a Candidate for Dark Matter.- On the Direct Detection of Dark Matter.- Galaxy Formation and Dark Matter.- Dark Energy: The Energy Balance of the Universe within the Standard Cosmological Model.- Cosmological Parameters from Galaxy Clusters: An Introduction.- Cosmological Constraints from Galaxy Clustering.- Dark Energy and the Microwave Background.- Models of dark energy.- Accelerating Universe: Observational Status and Theoretical Implications.- Dark Matter and Dark Energy Beyond the Standard Theory of General Relativity.- The Physics of Extra Dimensions.- Dark Energy from Brane-world Gravity.- The Issue of Dark Energy in String Theory.- Modified Gravity Without Dark Matter.- Avoiding Dark Energy with 1/R Modifications of Gravity.