The book gathers the lecture notes of the Les Houches Summer School that was held in August 2011 for an audience of advanced graduate students and post-doctoral fellows in particle physics, theoretical physics, and cosmology, areas where new experimental results were on the verge of being discovered at CERN. Every Les Houches School has its own distinct character. This one was held during a summer of great anticipation that at any moment contact might be made with the most recent theories of the nature of the fundamental forces and the structure of space-time. In fact, during the session, the...