bijx.lattice

Methods for manipulating lattice field configurations.

Includes both scalar and gauge fields, generally assuming periodic boundary conditions.

Functions

roll_lattice(lattice, loc[, invert])

Roll lattice fields by specified displacement with periodic boundaries.
bijx.lattice.roll_lattice(lattice, loc, invert=False)[source]

Roll lattice fields by specified displacement with periodic boundaries.

Performs a cyclic shift of lattice data, treating leading dimensions as spatial coordinates and trailing dimensions as field components (“channels”).

The default behavior “rolls into position”: to access the field value originally at site \((x+\text{loc})\), access the rolled lattice at site \(x\).

Parameters:

  • lattice – Lattice field array where leading dimensions correspond to spatial coordinates and trailing dimensions are field components.

  • loc – Displacement tuple specifying the shift in each spatial direction. Length must not exceed the number of spatial dimensions.

  • invert – If True, roll in the opposite direction (equivalent to accessing the field at \(x-\text{loc}\) when looking at site \(x\)).

Returns:

Shifted lattice array with the same shape as input.

Example

>>> lattice = jnp.arange(16).reshape(4, 4)
>>> shifted = roll_lattice(lattice, (0, 1))
>>> shifted[0, 0] == lattice[0, 1]
Array(True, dtype=bool)