Dark Matter Energy

The Key to the Stars

Dark Matter in the 2020s is a mystery but in the 2070s it's an emerging energy source. In the 2030s, the first Dark matter particles were observed at the Cern Facility in France Caen. Since then Civilizations have been slowly researching Dark Matter as a form of High output Energy production. By the 2050s it became understood that Nuclear Fusion still lacked the necessary output for FTL capabilities but could still run ships. Meaning the FTL engines of the future ships of humanity would require a secondary fuel source.
The race was started between South American Treaty Organization  and The United States of America with both giant countries working to invent Dark Matter Power Generators first. Dark Matter is the particle that binds the universe together and gravity accelerates its pull upon real space.
The current projected Age of the universe is also based on Dark Matter as it is theorised but highly believed that as the universe ages, more Dark Matter particles are created. However, they were extremely hard to find due to them not absorbing anything or reflecting anything. It wasn't until the Multi-Dimensional Window was invented in Scotland that they could see Dark Matter and was designed in order to view Exotic Particles. Finding a slew of new Particles and gaining various new discoveries that furthered the field of Faster Than Light Travel and provided the first major scientific basis of the Multiverse.

Current Status and Sophistication

Dark Matter Research is processing nicely, in 2062 CE, US Scientists in Area 51 created the first Prototype Generator that generates power by harvesting the 'liquid-like' energy and converting it into electricity by using AI and Nuclear Fusion reactors to fuel the process. By 2068, they managed to create Net Positive conversions and by 2071 managed to create a more stable prototype. The Key problem with the prototypes is that they require lots of space and power to run and using Fusion as a primary source of power is the cheapest option.
In SATO, they successfully create Net Positive conversions by 2070, the 6th of October in Venezuela. The next achievement that'll prove much harder is creating cables capable of pumping the sheer amounts of electricity the conversions produce and not overloading technology. The Poplar method is pump[ing the power in Mass batteries which then pump electricity to other systems but the cables capable of doing it right now are incredibly chunky and not optimal for integrating into vehicles, the chief of which is spacecraft.
Another problem is that since DM Generators are so large, you can't just put a subsidiary to start it up so they require power packs but even Fusion Power packs lack the power capacity alone to start up a DM Generator, meaning that more powerful Power Packs will be required for Hyperspace capable ships or that future power packs for such ships will need to be in Power Blocks, with dozens of power packs inserted just to start up a single generator. The current use of power is experimental sciences such as Portal tech, expanding AI capability, further advances in quantum technology and continued study of exotic matter.
Another purpose is Digital Currency Token generation, in order to give value to Digital Credits, energy tokens must be generated in a process similar to a Cyptocurrency like bitcoin except much more environmentally friendly because Dark Matter conversion costs no pollution even when started by Fusion because Fusion is a mostly clean process. 

Dark Matter, Renewable or Not?

In order to generate electricity, The harvesters harvest Dark Matter and then it feeds that matter into the converter and after a power-hungry process, convert it into electricity. In order to do any of this you new DM particles but luckily the current age of the universe means that there is plenty to gather from. Because the Universe generates so many particles it is considered renewable.
It is also considered 'Anti-Entropy' because obliviously high consumption of Dark Matter will extend the amount of time it takes for the Universe to die from Heat death, with less DM there s less stretching and less stretching means a longer-lived universe. 

Potential Technologies fueled by this

Dark Matter Energy is highly rich and is capable of fueling a wide variety of technologies. Much like how Fusion unlocked Mechs, clean cars and a Green energy economy. Dark Matter can unlock truly Sci-fi technologies. Because the process of converting Dark Matter into electricity exists and s being improved upon. There is future projects planned to further this technology of turning Dark Matter into standard matter meaning that the theorised 'Replicators' could produce goods from Dark matter and offset mass consumption in never before conceived ways. 
If done, then 3D printing could be revolutionised. You input a schematic or object into a replicator machine and it clones objects from Dark Matter in a process broadly called 'Anti Entropy'. Instead of converting matter into new types of matter. You'd literally be creating new matter and unlocking one of the fundamental building blocks of the Universe. Because this method of power is practically infinite, it is a viable option for big ships and expensive structures and projects.
This means that in the future, Fusion could be very much a commercial form of power and Dark Matter is a very state-orientated or military-orientated power generation method.

Prior to the Discovery at the Cern Facility in Caen, France. Dozens of organizations have been searching for Dark Matter in an attempt to find out more about the universe. However, in our 2020s, most research was focused around Nuclear Fusion.  In Neonphage, after Fusion was invented, it wasn't long before the insatiable energy demands of Humanity needed to be met once more. Dark Matter is promising because it is the one Energy source capable of upping Nuclear Fusion and inventing technologies that'll advance humanity possibly by many centuries.
FTL by Nuclear Fusion Power would likely be far too expensive and Fusion Technology is too novel even by the 2070s to be expected to output that kind of power.

If properly implemented, Novel Dark Matter Generators could be made to create the theorised Hype Gates that could hyper-accelerate ships into Hyperspace and decelerate them. If done properly, Humanity could install these hypegates into adjacent solar systems and begin to colonize them with trips being hours long rather then entire light years. Hyperspace for instance is immune to the effects of Dark Matter stretching the universe due to it being a Pocket Universe. Meaning that Hyperspace travel times will never truly change, even if the solar systems are many time apart from once they were.
At most the change between millennia is several seconds which could be further improved by Hypegates within Hyperspace itself.

As is often the case, Sci-Fi once again inspired new fields of science. In Half-Life 2, you can see the Universal Union or Combine using Dark Matter Generators to power the hyper advanced mult dimensional Dominion they held over Humanity and thousands of other worlds across realities. Many Scientists in Neonphage base their devices off Fictional Combine schematics, knowing that because the Multiverse exists, That means the Combine also exists and that if these Schematics work for them, then perhaps it'll work for Humanity within Neonphage's reality.
Though it is highly likely that the depictions were false, imaginary versions, Neonphage experimental facilities have managed to create pulse balls and transit these balls along streams of energy but prefer to keep these within piping for safety reasons. The Hardlight bridges have also been recreated, through the use of exotic particle named Hardlight, which is an Energy particle similar to light that can be solid. Thus why it is exotic. These bridges can be powered by Fusion and Dark Matter Generators.
Experiments with Portal technology emulate experiments with Valve's Portal setting, though the aesthetic varies to fit pragmatic purposes, America has taken many great strides in portal technology through the use of still ineffective but slowly improving Dark Matter Generators. Fusion Power packs are often use to offset the inefficies in these early generators and power sources.