The Multiverse Authority (MVA) is an interdimensional police agency responsible for preventing Quantum Tunneling (the technology that allows transit between parallal universes) from becoming a tool of crime and to apprehend all those who use it to escape justice and/or alter the affairs of parallel universes. The MVA was founded in a universe known as the "Alpha Universe". There it is under the authority of the United States with assistance from other high-technology nations.
Field agents of the MVA are divided into two interrelated groups. One group specializes in simple retrievals of Alpha Universe criminals who have used Quantum Tunneling to escape to another universe. The other group tracks criminals who commit "inter-universal crimes" such as smuggling.
The MVA was created in the Alpha Universe. A prominent U.S. Senator and member of the Senate Parallel Universe Technology Committee named Marcos Rodríguez championed the original Quantum Tunneling Research Project and was instrumental in raising the necessary funds. However, shortly after the first successful Quantum Tunnel jump, Rodríguez was indicted on charges of campaign finance fraud and accepting kickbacks from government contractors. Before he could be brought to trial, Rodríguez was able to access the prototype Quantum Tunneling Device and jump into the "Beta Universe." Due to the infancy of the technology, by the time he could be tracked, Rodríguez had already arranged the death of his Beta Universe "parallel universe version," also a U.S. Senator and had assumed his position.
A former Texas Border Patrol agent named Kyle Browning was hired to head security for the Quantum Tunneling Project and accompanied researchers on many of the first jumps. When one of the researchers made an unauthorized jump to escape from a tax fraud scandal, Kyle Browning successfully retrieved her.
The Multiverse Authority was formed to address the problems of the new technology and the criminals who were abusing it. Kyle Browning was made Head Field Agent and set in place many of the practices and procedures still used in the tracking and apprehension of criminals in other universes. He also coined the term "parallel universe retrieval," meaning not just the capture of criminals, but the act of escorting them back to the Alpha Universe for trial.
Some time after its creation, the Multiverse Authority appealed to all major technology producing Alpha Universe countries to contribute personnel and resources to the growing organization.
Billions of years ago out of the Big Bang came the universe, its galaxies and star systems. As time went on, the universe continuously split into an infinite number of parallel universes positioned next to our own in alternate dimensions, which are collectively called the multiverse. A parallel universe is another universe that is a copy of our own. It has stars and solar systems and galaxies. Some have planets that are exact copies of our Earth. Some of the parallel Earths are nearly identical to ours and some of them are drastically different.
These universes lie parallel to our universe in a six-dimensional continuum: three dimensions of space, and three of time. The dimensions of space (height, width, and depth) are familiar. The linear motion of time (past-present-future) can be considered one "dimension" of time. Time's other dimensions are made up of probability fields that are the "height" and "width" of time. In essence, these temporal dimensions encompass every possible past, present, and future that could exist, and does, "elsewhere" in the continuum.
In these higher temporal dimensions lie a potentially infinite number of parallel universes. The amount of divergence between universes - essentially the difference between their quantum signatures - determines how "far apart" they are in temporal terms.
Everything in a particular universe resonates on the subatomic level with a unique "signature," a particular sort of vibration on a quantum level. This signature is a constant. It cannot be changed by any known process. It is the basic foundation of existence. The quantum resonance signature is sort of a blueprint, a script, of its entire universe; the movements of each and every one of its particles in every moment of its time. This quantum signature is normally of little interest, since it is common to everything in the universe. However, objects from outside the universe have a different quantum signature. This includes people and objects from a parallel universe. A quantum scan can determine whether or not something is from the same universe as the scanner. If the quantum signature of the subject's home universe is known, then it can also be identified.
The more alike the quantum signatures are between universes, the more alike the universes themselves are. Minute differences in signatures don't drastically differentiate a timeline on the long term. This causes many universes to duplicate each other on a macroscopic scale, with altered events and personalities on a smaller scale.
Events and individuals often appear duplicated in these universes despite the larger-scale differences between them. Certain events are "synchronized" between the universes so they move in a parallel manner with different moments having their equivalents in various universes. Although the patterns of events move in similar manners in different these universes, the intentions and characterizations can be vastly different.
Thus the same people are created under significantly different circumstances, under which the same groups of people often meet in the same place and time in various universes, and the exact same genetic material is combined to form the exact same next generation. Of course the personalities of the people are often very different than in other universes because they grew up in different conditions. However, the lives of individuals from the universes are still often extremely similar, even down to the smallest details, despite larger difference in personality and attitude.
Although the quantum signature of matter cannot be altered by any known means, it is possible to place matter in a state of quantum flux. This causes the affected matter to become "unstuck" in the space-time continuum, shifting into another universe.
Essentially the process involves putting a subject into a state of quantum flux matched to the particular quantum resonance of the other universe. The affected matter shifts out of one universe and into the other. Returning to the original universe is a matter of once again placing the subject in a state of quantum flux and matching the resonance of the original universe. This is somewhat easier, since the subject's natural quantum signature always matches that of the subject's home universe.
The means of doing this involves using a "quantum tunnel", a weak point in the space-time continuum where different parallel universes come in contact. It can be thought of as a kind of keyhole between different universes. Normally, quantum tunnels are extremely small, and short-lived, of little concern to anyone. However, certain high-energy interactions can cause quantum tunnels to grow and de-stabilize, creating a more volatile interface between universes. Exposure to such a quantum tunnel can place objects in a state of quantum flux, causing them to shift between different parallel universes. This method of travel is called "Quantum Tunneling."