Parallel Universes
Oxford scientists claim parallel universes exist. The universe splitting constantly is seen as a way to combat the problems of time-travel paradoxes.
Exotic Matter
Theoretical matter with negative mass & energy density, that curves space – time in the opposite way to normal matter. Could be used to create wormholes.
Cosmic Strings
A theory about narrow tubes of energy stretching across the universe. Containing huge mass, if two approached each other, it could bend space – time around them.