How would you think people communicate with each other in a dimension where energy implode instead of explode?

I love theoretical questions that no one can really answer...yet. First of all, you are assuming that in such a Black Hole Universe that energy would implode and not explode. From the information you give, I am thinking that you are thinking that everything in such a universe would be opposite from our universe. As logical as this may seem, it is far more logical that in such a theoretical universe, everything in such a universe would function in just the same way as they do here. It is only when the two universes meet that the extremes of chaos would take place. After all, from their perspective, we are the opposite of them.

If energy imploded instead of exploded, or had the properties to only implode, instead of exploding. That would mean a purely magnetic plane of space fabric, versus the physical and volatile plane of space fabric that we sit on now. If that magnetic plane existed, we would need a level of technology that was able to manipulate gravity. Since the entire plane is gravitometric, we would be able to propel our ships across the entire plane because the gravity field would be all-encompasing. (spell that right?) We would then need a piece of tech that would reduce the stress of swirling gravity levels and directions on our ships and body to zero. Then we could exist, and anything we build could also exist. I dont think planets could exist on such a plane unless that type of space fabric allowed a celestial body to retain its own gravity type while it sits in its own sunken plane of existence. If a body were to sit on a purely magnetic-driven plane and sink into it halfway like we believe bodies do now.. then it should in theory reverse the effect of the surrounding plane and leave the planet to its own gravity type. That could be natural or artificial. Or we could artificially spin a body to have the proper gravity required to sustain life or humans.

That would have to be established before anything, our existence in such a place. Communications is easy! No radio waves. You would have to use tight beam laser-based transmissions. Which would be pretty simple if we were able to manipulate the gravity around our ships. Heres why: If we had gravity and antigravity tech down pat, we would be able to, through sensors, sense the deep of space for asteriods or whatever else there may be out there. Since magnetic fields are either attracted to each other, or oppose one another, the swirling fields of magnetic activity would be touching one another from one end of space to the other. It would be like pinging by sonar under water. The water carries the sound waves. In space, sensitive and powerful sensor suites could ping space in the same way for probably Light months or light years to locate a friendly base or ship. If every vehicle and base did the same thing continuously, then every unit would be aware of where all the others were. Maybe to a certain radius however.

SO! THEORETICALLY! You would then be able to use laser based communications. Tight beam is very precise and would need alot of power, but the burst of data shot from one ship would reach another. The only way this is possible is by pinging the ship in a different way, a ping pattern that lets the ship you want to recieve the message know to point its reciever array or whatever, towards your direction to accept the tight-beam laser message. Or.. much easier, each ship would have enough angles to be able to catch a laser based comm from any direction. Then the outer skin would have to be stuffed with sensor equipment. That would actually help recieving data, but not beam it out. So a comm laser gun or whatever would still be necessary.

Laser based tight-beam encrypted communications can only be accomplished when the exact location of both the communicating vehicles is known. That would be possible in a magnetic environment, where we are able to successfully and confidently manipulate and monitor the fields and their behaviors.

Makes sense huh?

You might want to consider buying a book about astrophysics, you gain a better grasp of matter-energy interactions...communication is not really relevant, since the universe you described is not likely to support any kind of life. Therefore no kind of communication. Also, Black Holes are a component of this universe, not an entire universe by themselves.

Stop and think..,

If energy were in a state of fusion then (supposing that life could exist) either my energy would be pulled into another's, or another's into mine.., hence.., We /they would be one and other than thought ,no need for communication.