Is FTL communication possible in theory? If yes/no then why?

To those who are evidently confused. Please actually read the article. If you have a specific questions about one of the points addressed in the article I will happily try to explain. But playing proverbial whack-a-mole when there is a perfectly valid authoritative source is silly.

There is no general disagreement that information is restricted to the speed of light and there is no general disagreement that certain phenomena that do not convey information can be detected to move superluminally. Shadows and lasers on distant objects is a textbook example. Similarly, in optics there is no causal paradox produced by the well documented existence of superluminal group velocities because there is no faster than light transmission of information for exactly the same reason there is no superluminal transmission of information when you flick a laser pointer over the moon: the velocity of the entire packet is still constrained by the speed of light. There is no paradox and there is no controversy. These are examples of well understood aparadoxical aproblematic superluminal but acausative phenomena.

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