The MULT is the current working theory of the cosmology in which our universe lies. It was initially penned by Jun Tatsuhi, a mid-ranking Mage stationed in New Dublin, current successor of the Tatsuhi Method, after a series of patents were filed on an invention he had made to enable traversal of the space between realities. According to the theory, with data recorded through repeated research trips, the universe is laid out as such;
It is currently believed that, if enough time is put into it, the courses and orbits of each specific reality we have documented can be charted, and that a proper interdimensional port can eventually be established. We would first have to travel to other realities, then find a way to mark each of them for future reference. Once we have the basic framework, it is believed that we will be able to build something attached to the outside of our universe, then we will be able to develop scheduled shuttles to other realities, a veritable port or station if you will.
What is currently possible is the ability to use this outside space as a method of effectively achieving FTL travel, a feat previously only usable by the space-bending mage families hailing from Russia. The only energy source powerful enough to ustain this technology is the burning of spiritual entities, who are simply upcycled back into the reincarnation queue as according to Einstein's Spirit Vault Hypothesis.
It is currently hypothesized that in 2025 this technology will be improved upon enough to be consumer grade, and by 2030 the Association will allow it to slip out of the dimensional interstice and into public knowledge.