Faster-Than-Light Solitons in 1 + 1 Dimensions

The existence of a faster-than-light particle is in direct opposition to Einstein's relativity and the principle of causality. However, we show that the theory of classical relativistic fields is not inherently inconsistent with the existence of the faster-than-light particle-like soliton solutions in $1+1$ dimensions. We introduce two extended KG models ($k$-fields) that lead to a zero-energy and a nonzero-energy stable particle-like solution with faster-than light speeds, respectively.