## Lattice Field Theory: Fermions

My in-progress, constantly changing notes on lattice field theory. This post is about Fermions on the lattice. Canonical Fermion Quantisation In the canonical quantisation formalism, one introduces creation and annihilation operators which obey anticommutation relations: $\{a_i^{+}, a_j\} = \delta_{ij}$ with all other anticommutators being...

## Lattice Field Theory: Gauge Fields

My in-progress, constantly changing notes on lattice field theory. This post is about Gauge fields on the lattice. Wilson’s Action For a lattice gauge field (which consists of the set of links between all lattice sites) $$\{U(b)\}$$, the Wilson action is given by $S(\{U(b)\}) = \sum_p S_p(U_p)$ where the sum is over all plaquettes in all o...

## How To Learn Quantum Field Theory (For Beginners!)

A review of Quantum Field Theory textbooks, lecture courses and online notes for beginners. This article is aimed at being a review as comprehensive as possible of the different resources (known to me) that are available for a beginner to self-learn QFT. My motivations for writing it are twofold; I would like to collect together a list of resou...

## A Short Introduction to Natural Units

A short introduction to the easy (but sometimes unnecessarily confusing) topic of natural units. Units and Dimensions Einsteins and Plancks The basic dimensions in physics are length, mass and time, which are commonly expressed in the SI system of units as the metre, the kilogram and the second. In particle physics, the typical scale of quant...

This post gives an extremely terse and brief overview of Fourier analysis (Fourier series and transform). Full derivations are given but other supplementary material should be used in addition to this post. Fourier Series Fourier’s theorem Statement A function is periodic with period $$2\pi$$ if $f(x) = f(x + 2\pi).$ $$f(x)$$ need only be g...