  These are introductory lecture notes aimed at beginning graduate students
covering fundamental concepts and ideas behind the renormalisation group. Our
main goal is to motivate it and then explore its consequences, in the context
of quantum field theory. We shall reproduce the standard results without
needing any mention of cancellation of infinities. To keep the story simple and
compact, we'll ignore the role of symmetry in this game. We'll also restrict to
scalar fields, and not mention neither fermions nor gauge fields. Moreover,
we'll only briefly mention the connection with statistical field theory.
  Knowledge of quantum mechanics and special relativity is essential. Prior
knowledge of quantum field theory is not required, however, this is not
designed to be an introduction to QFT, so it may not be the most pedagogical
way to introduce the topic. Previous familiarity with path integrals is also
not assumed.
