Kaluza-Klein mode
= Kaluza-Klein mode
{c}
{title2=$m_\ell=2\pi|\ell|/L$}
A Kaluza-Klein mode is a coefficient in a field expansion in eigenfunctions on compact extra dimensions. On a circle of circumference $L$, momentum is $2\pi\ell/L$, and a higher-dimensional massless field has lower-dimensional squared mass $(2\pi\ell/L)^2$. Nonzero modes give exponentially suppressed static-potential corrections at distances much larger than $L$.