Otherwise known as Dark Matter, WIMPs (Weakly-Interacting Massive Particles) may have had a significant role in creating the first stars, according to a paper in Physical Review Letters called “Dark Matter Capture in the first star: a Power source and a limit on Stellar Mass“. Since WIMPs are their own antiparticles, large collections of them may have annihilated each other to the point of outshining the fusion reactions of those initial stars.
The dark matter may have also provided an upper limit on the size of those initial stars. Because matter-antimatter reactions produce so much more energy than fusion reactions, those initial stars would more quickly reach their Eddington luminosity, or the upper limit of star brightness beyond which the star throws off its own mass due to excessive energy. This can be seen as a possible way that the first gases were dispersed across the universe, seeding later stars in the way that current supernovas do.
The first stars are hypothesized to have formed within reservoirs of dark matter, possibly providing the first “lumpy” features in the universe. As the stars grew in size, they accumulated dark matter through gravitation. As the dark matter accumulated at the center of the star, they began to annihilate, producing some of the first light in the universe.