Table of contents: Classical spin systems, order and disorder, introducing the Ising model and solving the 1d case, the transfer matrix, the Peierls argument; The quantum/classical correspondence, th . . . . .

The goal of electonic structure theory is to be predictive! Computational Electronic Structure Theory is an ever-growing field which combines theoretical physics and chemistry with computer science . . . . .

We present the screenplay of a physics show on particle physics, by the Physikshow of Bonn University. The show is addressed at non-physicists aged 14 and communicates basic concepts of elementar . . . . .

This essay sketches the development of X-ray Absorption Fine Spectroscopy (XAFS) ever since the second half of 20th century. At that time, synchrotrons started competing with X-ray discharge tubes as . . . . .

We give a summary of recent progress in the field of electronic structure calculations for materials with strong electronic Coulomb correlations. The discussion focuses on developments beyond the by n . . . . .

In this thesis we present a new formalism to study linear and non-linear response in extended systems. Our approach is based on real-time solution of an effective Schr"odinger equation. The coup . . . . .

A fully quantum-mechanical theory for the interaction of light and electron } hole excitations in semiconductor quantum-well systems is developed. The resulting many-body hierarchy for the correla . . . . .

The GWapproximation to the formally exact many-body perturbation theory has been applied successfully to materials for several decades. Since the practical calculations are extremely cumbersome, the . . . . .

The theory of highly excited semiconductors is dealt with from a many-particle point of view using the Green's function formalism.

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum . . . . .

This article aims to provide an introductory survey on quantum random walks. Starting from a physical effect to illustrate the main ideas we will introduce quantum random walks, review some of the . . . . .

This book introduces the theoretical description and properties of quantum fluids. The focus is on gaseous atomic Bose-Einstein condensates and, to a minor extent, superfluid helium, but the underlyin . . . . .

This article reviews the theory of electron-phonon interactions in solids from the point of view of ab-initio calculations. While the electron-phonon interaction has been studied for almost a century, . . . . .

This article presents a systematic theoretical enquiry concerning the conceptual foundations and the nature of phonon-mediated electron-electron interactions. Starting from the fundamental many-body . . . . .