The concept of an "eternal multiverse" encompasses the idea that there may be multiple universes or dimensions beyond our own, possibly with different physical laws or characteristics. However, it's important to note that the nature of the multiverse is still a subject of active scientific research and theoretical exploration, and there is no universally accepted theory that definitively describes or confirms its existence.
Given the speculative nature of the concept, it is difficult to make precise statements about how multiple dimensions within an eternal multiverse would behave. Different theoretical frameworks propose various mechanisms for the creation and evolution of universes or dimensions within a multiverse.
In some theories, such as inflationary cosmology, the expansion of space can lead to the creation of multiple "pocket universes" within a larger multiverse. These pocket universes may have different properties, including potentially different laws of physics. In this scenario, each universe or dimension within the multiverse could undergo its own expansion and evolution, potentially independent of others.
However, it's important to note that the specifics of how dimensions or universes within a multiverse would behave are highly speculative and depend on the particular theoretical framework being considered. The concept of an eternal multiverse is still an area of active research, and scientists are exploring different ideas and models to better understand its nature, if it exists at all.
It's worth mentioning that while the concept of a multiverse is intriguing and has captured the imagination of scientists and the public alike, it currently lies more in the realm of theoretical physics and speculative cosmology rather than established scientific fact.