UC Davis Study Questions Need for Dark Energy
Researchers propose Einstein's original equations, without a cosmological constant, may explain the universe's accelerating expansion.
Updated on Nov. 11, 2026 in Physics
A University of California, Davis study published earlier this year in Proceedings of the Royal Society A proposes a model of the universe that does not rely on dark energy. The authors argue that Einstein's original field equations, without the lambda cosmological constant he later discarded, may account for accelerated cosmic expansion.
Why it matters
The modern standard model of the cosmos, ΛCDM, depends on dark energy, a component that has never been directly observed or measured. An alternative explanation drawn from Einstein's original framework offers a different way to understand why the universe is expanding faster over time.
The researchers rewrote Einstein's equations in a self-similar form and tested whether small disturbances in a uniform Friedmann universe settle back or grow, finding that they grow rather than fade. The stub does not report how this result compares quantitatively with observational measurements, and whether the model reproduces observed cosmic expansion remains unaddressed.
The players
Albert Einstein
The physicist who published the General Theory of Relativity in 1916 and later introduced and discarded the lambda cosmological constant.
Edwin Hubble
The American astronomer whose 1929 observations demonstrated that the universe is expanding, prompting Einstein to abandon lambda.
Blake Temple
A UC Davis mathematics professor emeritus and co-author of the study proposing a universe model without dark energy.
University of California, Davis
The public research university whose researchers authored the study examining Einstein's equations without the lambda term.
The details
The team, which includes UC Davis mathematics professor emeritus Blake Temple, tested whether small disturbances in a uniform Friedmann universe settle back or grow. Their finding that disturbances grow rather than fade is presented as a route to accelerated expansion without invoking dark energy.
Timeline
1916: Einstein publishes his foundational General Theory of Relativity paper.
1917: Einstein introduces the lambda cosmological constant to his equations.
1929: Edwin Hubble demonstrates the universe is expanding, and Einstein discards lambda.
Late 1990s: Astronomers discover that the universe's expansion is accelerating.
Earlier in 2026: The UC Davis study is published in Proceedings of the Royal Society A.
The Big Picture
The study revisits the lambda cosmological constant that Einstein introduced in 1917 and discarded after Hubble's 1929 discovery. It proposes that his original field equations, without that term, may explain the accelerated expansion astronomers found in the late 1990s, challenging the reliance of the ΛCDM standard model on dark energy.
If the model holds up, it would change how cosmology accounts for the universe's expansion without requiring a component that has never been directly detected. Practical effects on daily life are not expected in the near term, since the work is theoretical and its commercialization timeline is not addressed.
The takeaway
Einstein's original equations, once set aside, are being tested again as a way to explain cosmic expansion without dark energy. Readers following cosmology should watch whether the model's predictions hold up against observational data.
Further reading
For more on the physics behind the cosmos, explore Physics coverage on Wisevoter.
Source note: This article includes information reported by Popular Mechanics.
