Decoherence: An Introduction

Abstract

In this paper I review the fundamentals of decoherence theory. Decoherence is viewed as a straightforward application of the general kinematical concept of a quantum wave function. Classical notions (such as ``particle") as well as secondary quantum concepts (such as ``observable'', superselection rule etc.) can be derived. Special emphasis is put on a precise and consistent interpretation of quantum states and processes.