{"id":1017718,"date":"2026-06-10T14:42:20","date_gmt":"2026-06-10T14:42:20","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/1017718\/"},"modified":"2026-06-10T14:42:20","modified_gmt":"2026-06-10T14:42:20","slug":"a-universe-without-dark-energy-mathematicians-challenge-standard-cosmology","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/1017718\/","title":{"rendered":"A Universe Without Dark Energy? Mathematicians Challenge Standard Cosmology"},"content":{"rendered":"

\"Dark<\/a>A new analysis argues that the standard cosmological model may be fundamentally unstable, raising questions about whether dark energy is really needed to explain the universe\u2019s accelerating expansion. Credit: SciTechDaily.com<\/p>\n

New mathematical research suggests dark energy may not be needed to explain the accelerating expansion of the universe, challenging the foundations of the standard cosmological model.<\/strong><\/p>\n

Mathematicians are questioning whether dark energy is actually responsible for the universe\u2019s accelerating expansion.<\/p>\n

In a new study published in Proceedings of the Royal Society A, researchers at the University of California, Davis<\/a> present mathematical evidence that instabilities within the Einstein-Euler equations suggest the current model of the expanding universe may not be viable. The Einstein-Euler equations combine general relativity and fluid dynamics and are widely used to model galaxies, black holes, and the expansion of the cosmos.<\/p>\n

The findings directly challenge the Lambda-cold dark matter model, the leading Big Bang cosmology framework.<\/p>\n

Study corresponding author Blake Temple, distinguished professor emeritus of mathematics at UC Davis, compared the standard cosmological model to a pencil balanced on its tip.<\/p>\n

\u201cAll the forces are in balance when a pencil is standing on end, so it is a \u2018solution of the equations,\u2019\u201d he said. \u201cBut it\u2019s unstable. Any breath of air and it falls away.\u201d<\/p>\n

Friedmann Spacetime Instability Challenges Dark Energy<\/p>\n

According to Temple, the team\u2019s calculations show that Friedmann spacetimes, the mathematical models used to describe cosmic expansion, are unstable at both small and large scales near the Big Bang. He said this makes them the most unstable solutions of all.<\/p>\n

\u201cUnstable solutions in physics and science are considered not physical,\u201d Temple said. \u201cYou\u2019ll never observe them in nature.\u201d<\/p>\n

Temple said this instability points to a simpler explanation that remains entirely within Einstein\u2019s original theory of gravity.<\/p>\n

\u201cThe instability of all Friedmann spacetimes to accelerated expansion suggests a simpler, more natural explanation for the acceleration of the universe than dark energy,\u201d he said.<\/p>\n

Why the Cosmological Constant Returned<\/p>\n

Dark energy was proposed nearly 30 years ago as a way to explain why the universe\u2019s expansion appears to be speeding up.<\/p>\n

The concept traces back to Einstein\u2019s 1915 equations of general relativity. To create a static universe, Einstein added an antigravity term known as the cosmological constant. After Edwin Hubble discovered in 1929 that the universe was expanding, Einstein reportedly referred to the cosmological constant as his \u201cbiggest blunder\u201d because, without it, his equations would have predicted expansion.<\/p>\n

In the 1990s, however, the cosmological constant was revived and linked to dark energy as a possible explanation for accelerating expansion. Modern cosmological models are built on the concept of a \u201cFriedmann universe,\u201d in which matter expands while remaining evenly distributed throughout space at any given time.<\/p>\n

Searching for an Alternative Explanation<\/p>\n

Temple and his colleagues believed there were mathematical problems with this picture, prompting them to investigate other possible causes of cosmic acceleration.<\/p>\n

\u201cOur first idea was that maybe the universe was expanding because there was a shockwave, and the anomalous acceleration was the expanding wave behind that shockwave,\u201d Temple said. \u201cThen we realized there\u2019s a family of self-similar solutions during the radiation epoch of the Big Bang, which might model that expanding wave.\u201d<\/p>\n

Self-similar equations describe systems that preserve the same overall pattern or structure across different scales.<\/p>\n

Self-Similar Equations Reveal Instability<\/p>\n

In the new study, the researchers used a self-similar version of Einstein\u2019s equations developed in earlier work to represent the standard cosmological model as a rest point of the equations. This approach allowed them to fully analyze the model\u2019s stability and, more broadly, the stability of all Friedmann spacetimes during the matter-dominated era of the Big Bang.<\/p>\n

\u201cWe prove that, like Einstein\u2019s static model, the Friedmann spacetimes are all unstable to radial perturbation at large length scales,\u201d Temple said. \u201cThis appears to rule out the Lambda-cold dark matter model as a viable stable solution of the Einstein equations of general relativity, with or without dark energy.\u201d<\/p>\n

\u201cThis means,\u201d he added, \u201cthat the Big Bang should generically look exactly like a Friedmann spacetime near the center of symmetry, but generically one should observe accelerations away from Friedmann far from the center.\u201d<\/p>\n

Cosmic Acceleration Without Dark Energy<\/p>\n

The researchers concluded that the universe\u2019s accelerating expansion emerges naturally from the Einstein-Euler equations and does not require either a cosmological constant or dark energy.<\/p>\n

Their findings also challenge the Copernican principle, the idea that Earth does not occupy a special location in the universe.<\/p>\n

\u201cBoth the Lambda-cold dark matter model and a spherically symmetric spacetime produce a special place where we must lie for the model to be physically plausible,\u201d Temple said. \u201cIf this principle rules out one, it has to rule out the other.\u201d<\/p>\n

Reference: \u201cThe instability of critical and underdense Friedmann spacetimes at the Big Bang as an alternative to dark energy\u201d by Christopher Alexander, Blake K. Temple and Zeke Vogler, 27 May 2026, Proceedings of the Royal Society A: Mathematical Physical and Engineering Science.
DOI:10.1098\/rspa.2025.0912<\/a><\/p>\n

The study was funded by the United Kingdom\u2019s Engineering and Physical Sciences Research Council and the American Institute of Mathematics SQuaREs Program.<\/p>\n

Never miss a breakthrough: Join the SciTechDaily newsletter.<\/a><\/b>
Follow us on Google<\/a> and Google News<\/a>.<\/b><\/p>\n","protected":false},"excerpt":{"rendered":"A new analysis argues that the standard cosmological model may be fundamentally unstable, raising questions about whether dark…\n","protected":false},"author":2,"featured_media":1017719,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[3845],"tags":[901,7017,9828,6769,74,70,13972,16,15],"class_list":["post-1017718","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-astronomy","tag-big-bang","tag-cosmology","tag-dark-energy","tag-physics","tag-science","tag-uc-davis","tag-uk","tag-united-kingdom"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/116726344356058685","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/1017718","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=1017718"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/1017718\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/1017719"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=1017718"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=1017718"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=1017718"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}