A nullverse is the idea that there can be something one step less than a Point/Pointverse. With 0-dimensionality being a single infinitely small, or even sizeless, location, -1 dimensionality would be the absence of any location.
A pointverse is a universe with 0 spatial dimensions meaning that it exists as a single point.
It contains no more space or positions inside it other than that single unique infinitely small position. It has no size at all. The point it exists as corresponds to the mathematical definition of a point which possesses no size or size equal to zero.
It can exist without time as well, with no time dimensions at all, existing in a perpetual state of "timelessness". Or it can have one or more temporal dimensions as normal.
It can be seen as a singularity as well.
Protoverse
A protoverse is a specific case of a pointverse.
A protoverse is said to exist within its own point of origin; the "singularity" or infinitesimally small point just before the Big Bang. In particular, it can be used to refer to the point leading up to our own universe.
The instant a protoverse "exists", it immediately turns into a Big Bang which like most universal births, creates the universe over a span of billions of years.
In the same way that this "explosion" creates the normal space dimensions of the resulting universe from the previous existing 0 space dimensions in the pointverse, it is possible that any time dimensions inside the resulting universe are created in that event and do not exist before it. In that case the pointverse existed out of time and there exists no "before" the Big Bang event for it, even though it itself already existed without time. It could be said that such protoverse was the cause for the Big Bang but not that it existed before the Big Bang.
Brane collisions create protoverses at their impact point, which then explode outwards into new branes.
An infinitesimal particle
According to modern physics, our universe consists of a huge number of particles that interact with each other within the framework of the fundamental forces of nature. However, there is a theory that each of these particles itself can be a miniature universe containing multiverse structures and entities.
The idea is that inside each infinitesimal particle there is its own world, with its own laws of physics and entities. These multiverse structures can contain a variety of objects, from galaxies and star systems to the smallest elementary particles.
