  We present a relativistic three-body equation to study the stability of the
isolated three-body system and the correlations in a medium of finite
temperatures and densities. Relativity is implemented utilizing the light front
form. Using a zero-range force we find the relativistic analog of the Thomas
collapse and investigate the possibility that the nucleon exists as a Borromean
system. Within a systematic Dyson equation approach we calculate the three-body
Mott transition and the critical temperature of the color-superconducting
phase.
