Jul 22, 2026 11:42 PM
Does dark energy really exist? Our work identifies cracks in the foundations of today’s cosmological model
https://theconversation.com/does-dark-en...del-284368
EXCERPT: But the ΛCDM model has come under increasing scrutiny as new data has emerged. [...] It has been noted that the model’s past successes may partly be due to “confirmation bias” – the unconscious tendency to favour information that supports our existing beliefs while giving less attention to information that challenges them. ... Most cosmologists remain unconvinced by such criticism and are instead persuaded by the multiple lines of evidence that the universe’s expansion is accelerating.
[...] The acceleration inferred from supernovae cannot therefore be due to dark energy. Rather, it is probably an illusion, because we are “tilted observers”. This is because of Earth’s specific location in the cosmos, where our neighbouring galaxies are participating in a large-scale but localised streaming motion called the bulk flow.
The relationship between the intrinsic brightness of Type Ia supernovae and their distance has been crucial to the idea of dark energy. However, this relationship may not be as robust as was first assumed. Astronomers in South Korea found evidence that the ages of the white dwarf stars that produce Type Ia supernovae (their progenitors) affect their brightness. However, this has been challenged by another team.
When we corrected for the dependence of the intrinsic brightness on the progenitor age, the indication is that the universe is decelerating, rather than accelerating.
This is just as is expected for a universe without dark energy. But it will come as a surprise to most cosmologists who believe that there is compelling independent evidence for ΛCDM, in particular from studies of the CMB. But CMB temperature fluctuations are not influenced by dark energy. Rather, they are related to the spatial curvature of the universe, the baryon density, and the dark matter density.
Whether dark energy is still a valid inference thus depends on whether the distribution of matter in the universe is indeed isotropic – exactly the same in all directions. Observations suggest otherwise. If these findings are confirmed, they could signal a paradigm shift in cosmology... (MORE - missing details)
https://theconversation.com/does-dark-en...del-284368
EXCERPT: But the ΛCDM model has come under increasing scrutiny as new data has emerged. [...] It has been noted that the model’s past successes may partly be due to “confirmation bias” – the unconscious tendency to favour information that supports our existing beliefs while giving less attention to information that challenges them. ... Most cosmologists remain unconvinced by such criticism and are instead persuaded by the multiple lines of evidence that the universe’s expansion is accelerating.
[...] The acceleration inferred from supernovae cannot therefore be due to dark energy. Rather, it is probably an illusion, because we are “tilted observers”. This is because of Earth’s specific location in the cosmos, where our neighbouring galaxies are participating in a large-scale but localised streaming motion called the bulk flow.
The relationship between the intrinsic brightness of Type Ia supernovae and their distance has been crucial to the idea of dark energy. However, this relationship may not be as robust as was first assumed. Astronomers in South Korea found evidence that the ages of the white dwarf stars that produce Type Ia supernovae (their progenitors) affect their brightness. However, this has been challenged by another team.
When we corrected for the dependence of the intrinsic brightness on the progenitor age, the indication is that the universe is decelerating, rather than accelerating.
This is just as is expected for a universe without dark energy. But it will come as a surprise to most cosmologists who believe that there is compelling independent evidence for ΛCDM, in particular from studies of the CMB. But CMB temperature fluctuations are not influenced by dark energy. Rather, they are related to the spatial curvature of the universe, the baryon density, and the dark matter density.
Whether dark energy is still a valid inference thus depends on whether the distribution of matter in the universe is indeed isotropic – exactly the same in all directions. Observations suggest otherwise. If these findings are confirmed, they could signal a paradigm shift in cosmology... (MORE - missing details)