A multiverse is a theoretical concept that suggests the existence of multiple universes beyond our own. These universes may have different physical laws, dimensions, and histories.
Currently, scientists study multiverses through mathematical models and theories such as string theory and quantum mechanics. They also use data from observations of the universe and experiments to test these theories.
A subuniverse is a smaller universe that exists within a larger multiverse. It may have its own unique set of physical laws and characteristics that differ from the larger universe.
Currently, there is no direct observational evidence for the existence of multiverses. However, some theories, such as cosmic inflation and the multiverse interpretation of quantum mechanics, suggest the possibility of indirect evidence through observations of the universe.
Multiverses are currently just a theoretical concept and have not been proven to exist. While some theories suggest the possibility of indirect evidence, further research and advancements in technology are needed to prove the existence of multiverses.