The Standard Model of elementary particles and interactions is one of the best tested theories in physics. It has been found to be in remarkable agreement with experiment, and its validity at the quantum level has been successfully probed in the electroweak sector. In spite of its experimental successes, though, the Standard Model suffers from a number of limitations, and is likely to be an incomplete theory. It contains many arbitrary parameters; it does not include gravity, the fourth elementary interaction; it does not provide an explanation for the hierarchy between the scale of electroweak interactions and the Planck scale, characteristic of gravitational interactions; and finally, it fails to account for the dark matter and the baryon asymmetry of the universe. This led particle theorists to develop and study various extensions of the Standard Model, such as supersymmetric theories, Grand Unified Theories or theories with extra space-time dimensions - most of which have been proposed well before the experimental verification of the Standard Model. The coming generation of experimental facilities (such as high-energy colliders, B-physics experiments, neutrino superbeams, as well as astrophysical and cosmological observational facilities) will allow us to test the predictions of these theories and to deepen our understanding of the fundamental laws of nature.

This book is a collection of lectures given in August 2005 at the Les Houches Summer School on Particle Physics beyond the Standard Model. It provides a pedagogical introduction to the various aspects of particle physics beyond the Standard Model, covering each topic from the basics to the most recent developments: supersymmetric theories, Grand Unified Theories, theories with extra dimensions, flavour physics and CP violation, neutrino physics, astroparticle physics and cosmology.
-Provides a pedagogical introduction to particle physics beyond the Standard Model
-Covers the various aspects of particle physics beyond the Standard Model
-Addresses each topic from the basics to the most recent developments
-Addresses both the theoretical and phenomenological aspects of the subject
-Written in a pedagogical style by leading experts in the field

This Carg ese school of Particle physics is meant to bridge the narr- ing gap between astrophysical observations and particle physics. The lectures supply the students with a theoretical background which covers severalaspectsofthecosmologicalscenario: matter-antimatterasym- try, the nature of dark matter, the acceleration of the expansion and the cosmological constant and the geometry of the universe as well as m- ernviewsonparticlephysicsincludingsupersymmetry, extradimensions scenarii and neutrino oscillations. ix Preface TheinvestigationofnuclearabundancesbyAlpher, Bethe, andGamow (1948) was the ?rst intrusion of subatomic physics into cosmology. In contrast with their assumption, most nuclear species are now known to be produced in stars, but their bold step led to predictions which have largely been proven to be right: -a crude estimate of the densities during primordial nucleosynthesis -the presence of a residual 3K radiation today. the issues they addressed are still relevant. The origin of matter is not fully understood, and the CMB has grown into a powerful tool to inv- tigate the early eras of the universe. The progress of cosmological observations has now led to a 'standard' slow-roll in?ation model, which accounts quantitatively for many - served features of the universe. As the lectures will show, it still leaves large unchartered areas, and the underlying particle physics aspects are yettobeelucidated.