|The purpose of these notes is to point out a few key results in quantum mechanics,
statistical physics and many-body theory that should be useful to understand the
application of advanced numerical methods to condensed matter. The degree of
sophistication necessary to understand these methods is very high. The impor-
tant developments in the field have been achieved by people familiar with all the
anlytical tricks of the trade.
These notes will not be very useful to learn the topics if you have never heard
of them before. They should be seen as a summary of important concepts and
methods to know in the context of this School.