Nov 29, 2025 00:00:00

University of Tokyo finally succeeds in direct observation of dark matter

Dark matter, which has been shrouded in mystery for nearly a century, may finally be making its appearance. Professor Tomonori Toya of

the University of Tokyo has announced that he has detected gamma rays that provide direct evidence of dark matter from observational data obtained by NASA 's Fermi Gamma-ray Space Telescope.

Press Releases - Graduate School of Science and Faculty of Science, The University of Tokyo
https://www.su-tokyo.ac.jp/ja/press/10983/

20 GeV halo-like excess of the Galactic diffuse emission and implications for dark matter annihilation - IOPscience
https://iopscience.iop.org/article/10.1088/1475-7516/2025/11/080

[2507.07209] 20 GeV halo-like excess of the Galactic diffuse emission and implications for dark matter annihilation
https://arxiv.org/abs/2507.07209

In a First for Humanity, Scientists May Have Finally Seen Dark Matter - SciTechDaily
https://scitechdaily.com/in-a-first-for-humanity-scientists-may-have-finally-seen-dark-matter/

https://t.co/dsEJlcY7b5 The University of Tokyo issued a press release. According to altmetrics, it has been covered by over 40 media outlets around the world, including BBC, NBC, Guardian, and Newsweek. However, it was completely ignored by Japanese media, so I'm going to sulk in bed today.

— Tomonori Totani (@tomonoritotani) November 26, 2025

◆What is dark matter?
In the early 1930s, Swiss astronomer Fritz Zwicky noticed that many galaxies were moving too quickly for their visible mass to explain, and he proposed that an additional gravitational force was needed to hold them together, and that this was due to an invisible structure: dark matter .

Why is dark matter so difficult to detect?
Dark matter cannot be observed directly because its particles do not interact with the electromagnetic force and do not absorb, reflect, or emit light.

Searching for WIMPs and gamma rays
Many scientists believe that dark matter is composed of weakly interacting heavy particles known as ' WIMPs .' Based on the theory that when two WIMPs collide, they annihilate each other , emitting high-energy particles, including gamma-ray photons, they have studied the regions where dark matter is thought to be most abundant. Professor Toya believes he has identified gamma rays from new observational data from the Fermi Gamma-ray Space Telescope that are consistent with the results predicted by the annihilation of dark matter particles.

The 20 GeV gamma-ray halo surrounding the Milky Way Galaxy
'We detected very energetic gamma rays with photon energies of 20 GeV extending into a halo-like structure towards the centre of the Milky Way. This gamma-ray emission component closely matches the shape expected from a dark matter halo,' said the professor.

Further analysis revealed that the distribution of gamma-ray intensities is consistent with the levels predicted for the annihilation of a hypothetical WIMP with a mass about 500 times that of a proton. Estimates of the WIMP annihilation rate based on the gamma-ray brightness also fall within established theoretical predictions.

Promising signals, but verification is yet to come
The measurements cannot be easily explained by other known astronomical processes or common sources of gamma rays, so the data could be strong evidence of dark matter radiation, which researchers have been trying to detect for decades.

Next steps to confirm your findings
While Professor Toya is confident, he emphasizes that his findings need to be independently verified by other researchers. One way to strengthen the evidence is to identify similar gamma-ray signals in other places with high dark matter densities. Dwarf galaxies in the Milky Way's halo are considered particularly promising candidates. 'This may be possible as more data is accumulated, and it would provide even stronger evidence that the gamma rays originate from dark matter,' he says.