1. The problem statement, all variables and given/known data A claim is made that a new force field F(x) (independent of the four-velocity) is discovered which induces on a mass m a 4-acceleration a = du/dτ = F(x)/m at position x. Would this be consistent with special relativity? Why or why not? 2. Relevant equations 3. The attempt at a solution Consistent with relativity - if not, I would looking for some violation of maximum speed - light velocity or relativity prinicipel. Some hint please?