# Position and momentum space

The pulse space is a three-dimensional coordinate system, with each basis vector corresponds to a pulse of the corresponding direction in space. The pulse space is a subspace of the phase space, and thus differ from the spatial domain. By assigning appropriate coordinates can put up with the momentum space a phase space.

## Quantum mechanics

In quantum mechanics the states of a system are described by wave functions, which can each be represented in the local or in momentum space. Depending on the problem the bill may be more favorable in one of the rooms. The two types of representation are related by the Fourier transform:

- Position-space wave function
- Momentum space wave function

With

- The reduced Planck 's constant
- The pulse
- The imaginary unit

## Solid State Physics

In solid-state physics, the terms momentum space and reciprocal space and reciprocal lattice are used analogously.

- Quantum physics