ok let me get specific. the theory states that there exist not one but many universes...........a multiverse if u will. each universe is similar to every other universe barring certain differences; these differences maybe as small as the fact that the computer on ur table is slightly towards the right or as big as the fact that u r reading someone else's post and i m Dr David Deutsch! now according to Dr David Deutch, when we eventually do travel in time (non-linerly) we do not go back in time in our universe but appear in the past of another universe. now if that is the case, then the TIME PARADOX does not hold true as i m pretty sure the death of my grandfather in another universe will have little impact on my universe and thus will not result in my non-existence.
Now wat i m really looking for are alternate theories or rather theories that either support or contradict this proposed theory. Thank You for ur responses.