Static kink bound in a mass-deformed spherical sigma model
= Static kink bound in a mass-deformed spherical sigma model
{title2=$E\geq rm|T|$}
For $T=-[\cos\phi]_{-\infty}^{+\infty}/2$, complete the static <energy> into squares $(\phi_x\mp m\sin\phi)^2$ and $\sin^2\phi\,\alpha_x^2$. The boundary term is $\pm rmT$. A $T=1$ saturating <kink> is $\phi=2\arctan e^{m(x-x_0)}$, with constant $\alpha$ and <mass> $rm$. This is a model-specific <Bogomolny bound>.