Chapter 1 Introduction to stochastic geometry Daniel Hug and Matthias Reitzner Abstract This chapter introduces some of the fundamental notions from stochastic geometry. Background information from convex geometry is provided as far as this is required for the applications to stochastic geometry. First, the necessary definitions and concepts related to geometric point processes and from convex geometry are provided. These include Grassmann spaces and in- variant measures, Hausdorff distance, parallel sets and intrinsic volumes, mixed vol- umes, area measures, geometric inequalities and their stability improvements. All these notions and related results will be used repeatedly in the present and in subse- quent chapters of the book. Second, a variety of important models and problems from stochastic geometry will be reviewed. Among these are the Boolean model, random geometric graphs, intersection processes of (Poisson) processes of affine subspaces, random mosaics and random polytopes. We state the most natural problems and point out important new results and directions of current research. 1.1 Introduction Stochastic geometry is a branch of probability theory which deals with set-valued random elements. It describes the behavior of random configurations such as ran- dom graphs, random networks, random cluster processes, random unions of con- vex sets, random mosaics, and many other random geometric structures. Due to its Daniel Hug Karlsruhe Institute of Technology, Department of Mathematics, 76128 Karlsruhe, Germany. e- mail:
[email protected] Matthias Reitzner Universitat¨ Osnabruck,¨ Institut fur¨ Mathematik, Albrechtstraße 28a, 49086 Osnabruck,¨ Germany. e-mail:
[email protected] 1 2 Daniel Hug and Matthias Reitzner strong connections to the classical field of stereology, to communication theory and spatial statistics it has a large number of important applications.