In astronomy and cosmology, the dark fluid theory attempts to explain dark matter and dark energy in a single framework, as suggested by cosmologist Alexandre Arbey in 2005. The theory proposes that dark matter and dark energy are not separate physical phenomena, nor do they have separate origins, but that they are strongly linked together and can be considered as two facets of a single fluid. At galactic scales, the dark fluid behaves like dark matter, and at larger scales its behavior becomes similar to dark energy.