The concept of time travel in physics seems a bit different, to me, than time-travel in sci-fi.
The time-space situation of an object in a worm-hole is what gets altered, in a huge way, according to the worm-hole time-travel theory. But that doesn't mean travel backwards in time is possible. At least that's my picture of it, but I am far from an expert.
The worm-hole time travel idea seems like an exaggerated version of the example given in beginner physics courses: an astronaut leaves earth, travels at speeds near the speed of light, then returns to earth having aged much less in his travel time than the people earth have aged.
Time, in this case, is shown to be relative and time-travel is shown to be theoretically possible. But it's not like the astronaut can go back and kiss his mother when she was a baby in the crib. In concrete terms, that is still impossible.
In a purely physical way, there is no past to travel back to. It doesn't exist anymore. Neither does the future. Only the present exists, physically.