![[Pasted image 20251024134337.png|400]] The [[Wavenumber]] is a property of a [[Spatial Wave]] that is analogous to the [[Angular Frequency]] of the wave in respect to space, and is commonaly denoted as $k$. $\huge k = \frac{2\pi}{\lambda} $ Where $\lambda$ is the [[Wavelength]], meaning that $k$ and $\lambda$ have the same relation as [[Angular Frequency]] $\omega$ and [[Period]] $T$. Sometimes the wave number is denoted as the 'wave number [[Vector|vector]]', whose magnitude is the wavenumber and direction is perpendicular to the [[Wavefront]] (the direction of the [[Wave]]). $\huge \vec k \cdot \vec k \vec = \frac{\omega^{2}}{c^{2}} $