This book arose from lectures I gave at the Free University Berlin over a number
of years. The lectures were intended as two-semester+ introductions to graduate
students who intended to start theoretical research work either in many-body physics
or in particle physics.
Being a general broadly-based introduction, the book requires extension into
two directions which have to be subjects of continuing specialized courses. What is
needed is
• a more detailed account of the exciting developments in nonabelian gauge
theories which has taken place over the last decade establishimg quantum
chromodynamics as a most probably true theory of strong interactions.
• a proper presentation of the field-theoretic explanations of the critical proper-
properties of many-body systems near second-order phase transitions.
Kleinert H.