Hi /sci/, I'm currently in the process of trying to write a scifi novel, I have plenty of ideas, but I would like them to be grounded in hard science at least as much as it is possible.

That being said, which of the following FLT or sublight relativistic travel methods would you consider the most plausible?

FTL:
1. Artificial wormholes: A ship such as pic related able to generate a stable wormhole in front of it.

2. Warp aka Alcubierre Drives: Warping spacetime in a bubble around the ship, contracting spacetime ahead of itself and expanding it behind.

3. Hyperspace mumbo-jumbo: The ship is able to access another dimension aka subspace or hyperspace, through which it can travel faster. (Least believable IMHO)

I am also aware that for any realistic interstellar-spanning empire, some form of FTL communication would also need to exist to ensure its cohesion.

Which of these sounds more realistic according to our current scientific knowledge? How would you solve the FTL communication problem? Is FTL at all a realistic perspective or should the direction of my story switch to one using sublight travel methods? (Such as magnetic plasma sails which I believe are more realistic and grounded in current tech)

Your feedback is much appreciated.