Notation and Conventions

Bare values are given in Planck units where $M_p \approx 1.22 \times 10^{19} GeV$. The FRW metric is taken to be $g_{\mu\nu} = diag\{1,-a^2,-a^2,-a^2\}$ meaning bare time is measured in physical units and bare distances are measured in comoving coordinates. Variables that have been rescaled in the program are denoted by the subscript $pr$. Repeated indices are summed unless otherwise indicated. Overdots indicate differentiation with respect to the bare time $t$ while primes indicate differentiation with respect to the program time $t_{pr}$.

Generic properties of fields are indicated by using $f$ for the field variable. Subscripts such as $f_i$ will be used only where needed for clarity. $F_k$ and $f_k$ refer to continuous and discrete Fourier transforms of $f$ respectively. These are discussed at greater length in section 6.3.

The scale factor and time are initially set to $1$ and $0$ respectively for convenience.

Frequently the documentation refers to files included in the LATTICEEASY distribution, or to variables and/or functions in the program. These file names are written in a typewriter font, as in latticeeasy.cpp. Output files created by the program are printed in the same way. The functions and variables in the program are also in typewriter font, but they have also been slanted, as in nflds and potential_energy(). (An exception to this is when program variables appear in equations, in which case they are displayed in the usual equation format for readability.) Functions will always be indicated with parentheses, but the arguments to the function will generally not be included.