Researchers from the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen and the Transylvanian University of Brașov in Romania have proposed an alternative explanation for the universe's accelerating expansion. Their study suggests that an extended theory of gravity, known as Finsler gravity, can account for this phenomenon without requiring the hypothetical "dark energy" term, which is often used in standard cosmological models.
Context of Universal Expansion
The accelerating expansion of the universe represents an unresolved question in physics. Current cosmological models, based on Einstein's general theory of relativity and the standard model of particle physics, typically incorporate "dark energy" to account for this expansion. The nature and origin of dark energy remain unidentified.
Cosmologists utilize Einstein's general theory of relativity and the Friedmann equations to model cosmic evolution. To align these equations with astronomical observations of an accelerating universe, a "dark energy term" is manually added, as it is not inherently derived from the standard theory itself.
Introducing Finsler Gravity
The research team investigated Finsler gravity, an extension of general relativity that employs a broader description of spacetime geometry. This approach has been shown to describe the gravitational behavior of gases more precisely than standard general relativity, a factor deemed crucial for modeling the universe on a large scale.
Implications for Cosmic Expansion
When Finsler gravity was applied to the Friedmann equations, the resulting modified equations, termed Finsler-Friedmann equations, inherently predicted an accelerating universe. This prediction occurred even in empty space, without the need for an additional "dark energy" term or other assumptions.
Christian Pfeifer, a ZARM physicist and team member, indicated that these findings suggest the accelerated expansion of the universe might be explained, at least in part, through a generalized spacetime geometry. He added that this perspective offers new possibilities for understanding cosmic laws.
Research Publication
The study was published in the Journal of Cosmology and Astroparticle Physics.