A new fully non-linear reconstruction algorithm, based on the least-action principle and extending the Fast Action Minimisation method by is presented, intended for applications with the next-generation massive spectroscopic surveys. Its capability of recovering the velocity field starting from the observed density field is tested on dark-matter halo catalogues simulation to trace the trajectories of up to 10^6 haloes backward-in-time. Both in real and redshift-space it successfully recovers the peculiar velocities. The new algorithm is first employed for the accurate recovery of the Baryonic Acoustic Oscillations (BAO) scale in two-point correlation functions. Tests on dark-matter halo catalogues show how the new algorithm successfully recovers the BAO feature in real and redshift-space, also for anomalous samples showing misplaced or absent signature of BAO. A comparison with the first-order Lagrangian reconstruction is presented, showing that this techniques outperforms the linear approximation in recovering an unbiased measurement of the BAO scale. A second version of the algorithm accounting for the survey geometry and the bias of tracers is finally tested on low-redshift galaxy samples extracted form mocks specifically designed to match the SDSS-DR12 LRG clustering. The analysis of the anisotropic clustering indicates the non-linear reconstruction as a fundamental tool to brake the degeneracy between redshift-space distortion and the Alcock-Paczynski effect. Finally the application to the cosmic voids analysis is introduced, showing the great potentiality of a non-linear modelling of the velocity field in restoring the intrinsic isotropy of voids.

The amount of cosmological data has dramatically increased in the past decades due to an unprecedented development of telescopes, detectors and satellites. Efficiently handling and analysing new data of the order of terabytes per day requires not only computer power to be processed but also the development of sophisticated algorithms and pipelines. Aiming at students and researchers the lecture notes in this volume explain in pedagogical manner the best techniques used to extract information from cosmological data, as well as reliable methods that should help us improve our view of the universe.

A coherent introduction for researchers in astronomy, particle physics, and cosmology on the formation and evolution of galaxies.

History and Overview -- Is Nature Generic? -- Evolution of Ideas in Modern Cosmology -- Mathematical Cosmology -- Constraints and Evolution in Cosmology -- Cosmological Singularities -- Exact Cosmological Solutions -- to Cosmological Dynamical Systems -- Astrophysical and Observational Cosmology -- The Quest for the Cosmological Parameters -- Modern Cosmological Observations -- Cosmological Perturbations -- Dark Matter: A Particle Theorist's Viewpoint -- Particle and String Cosmology -- An Introduction to Particle Physics -- Quantum Cosmology -- Inflationary Cosmology -- String Cosmology -- Brane Cosmology.

The Restless Universe: Applications of Gravitational N-Body Dynamics to Planetary Stellar and Galactic Systems stimulates the cross-fertilization of ideas, methods, and applications among the different communities who work in the gravitational N-body problem arena, across diverse fields of astrophysics. The chapters and topics cover three broad the