We can`t see multiverse. it exist theoretically, but we can`t see them. Instead of saying that it is due to the event horizon that prevents light from entering-reaching us. I would like to post a speculation. Is it possible that it is due to the fact that our companion universe is full and compact with superclusters, clusters and galaxies, thus lights from galaxies in our companion universe cannot pass through them and creates a shadow, which make us unable to "see" them. I think the multiverse is just invisible due to the fact that we lie in their shadows.

You might like this: http://iai.tv/video/how-to-find-a-multiverse

 

(Note: I haven't watched it and don't endorse her ideas, but they are interesting.)