Discrete and Continuous Models and Applied Computational ScienceDiscrete and Continuous Models and Applied Computational Science2658-46702658-7149Peoples' Friendship University of Russia named after Patrice Lumumba (RUDN University)8540Research ArticleTachyon Gas as a Candidate for Dark MatterRylovY A-Institute for Problems in Mechanics, Russian Academy of Sciences15022013215917308092016Copyright © 2013,2013In the physical geometry (i.e. in geometry, described completely by its world function) identical geometric objects have identical description in terms of the world function. As a result spacelike straight segment is a three-dimensional surface even in the space-time geometry of Minkowski. Tachyons have two unexpected properties: (1) a single tachyon cannot be detected and (2) the tachyon gas can be detected by its gravitational inﬂuence. Although molecules (tachyons) of the tachyon gas moves with superluninal velocities, the mean motion of these molecules appears to be underluminal. The tachyon gas properties diﬀers from those of usual gas. The pressure of the tachyon gas depends on the gravitational potential and does not depend on temperature. As a result the tachyon gas may form huge halos around galaxies. These halos have almost constant density, and this circumstance can explain the law of star velocities at the periphery of a galaxy. Properties of the tachyon gas admit one to consider it as a dark matter.discrete geometrytachyondark matterdark energyrotation curvesдискретная геометриятахионтёмная материятёмная энергиякривые вращения