Permeability tensor

The permeability tensor is a mathematical way to describe how easily magnetic fields pass through a material, especially when that material isn't the same in all directions. Imagine a fabric that allows magnetic lines to go through more easily in one direction than another; the permeability tensor captures this complex behavior by relating the magnetic field to the magnetic flux at every point in the material. Unlike a simple number, the tensor accounts for directional differences, providing a detailed map of how the material interacts with magnetic fields depending on orientation.