See discussion on iFactor for background
If time and space gain an i factor or in fact become mathematically imaginary. (gaining a negative square route factor) I will from this point on refer to it as imaginary space or iSpace. Such conditions apply where speeds exist between the ranges of just over light speed and light speed squared ( where time and space become negative).
Since time, space and mass in iSpace are simultaneously increased and inverted (Positive and negative in equal proportion) they would cancel each other out as viewed by the outside observer, and thus still appear as Einstein described them.
Since objects pulled into a black hole are being pulled an external force, then if might be possible for such an object to exceed light speed. Such an object would appear forever trapped at the advent horizon, but would in fact be subject to iSpace relativity. The same might also hold true for Tachyons( Unless they travel at light speed squared in which case they might be subject to negative relativistic effects such as negative mass, length and reverse movement through time.
Just a thought.
Until next time.