Category Archives: Space

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Min kronik i Politiken i dag: “Robotterne er ved at ændre vores billede af universet”. Link til online versionen her (under paywall): https://politiken.dk/del/QIFYjSAHS1LQ

Kronikken handler om, hvordan robotter og kunstig intelligens ikke kun er ved at ændre samfundet, men også vores måde at se universet på. Nye teleskoper og enorme datamængder gør det muligt at måle kosmos med en præcision, der nu udfordrer den model, fysikere længe har brugt til at beskrive universet. Jeg skriver som professor i teoretisk kosmologi og som forsker midt i dette felt. Med kosmologien som eksempel er min pointe, at videnskabelige paradigmeskift ikke kun begynder med nye teorier, men også med de teknologier, der gør nye sprækker i verdensbilledet synlige.

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“The H0 World Cup” is out (see links below). They have made a thorough update of “The H0 Olympics” paper from 5 years ago by the same core author group, with an extensive comparison of models in light of new data. This independent analysis shows that the Cold NEDE and Hot NEDE (with DRMD) models are among the leading models for solving the Hubble tension.

While Cold NEDE is clearly among the leading models (in the EDE class), Hot NEDE with DRMD (in the class of dark radiation models) is only among the leading models when allowing for running and running of the running of the spectral index, as also shown in our recent paper (“The End of the First Act”). In the short summary paper, this discussion is not included, and for the full picture of the DRMD model, one should read their second long paper (see links below).

The first short “The H0 World Cup” summary paper: https://arxiv.org/abs/2607.13282

The second long “The H0 World Cup” complete paper: https://arxiv.org/abs/2607.13283

For a YouTube video seminar where I discuss the Cold NEDE and Hot NEDE with DRMD models, and their similarities and differences, see f.ex.: https://www.youtube.com/live/VaaCsy4aPV0?si=bYtvFCzJS2AsXg5w

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A new early-universe explanation of the DESI anomaly connecting to the predictions of our solution to the Hubble tension in collaboration with Mathias Garny and Florian Niedermann: https://arxiv.org/abs/2512.15870

The presence of a Dark Acoustic Oscillation (DAO) near the actual BAO may appear as a single BAO-only feature with a slightly shifted peak position, which could bias the DESI BAO measurements, thereby explaining the anomaly in the DESI DR2 data without invoking late-time-evolving Dark Energy. The DAO predicted in our model for solving the Hubble tension, Hot New Early Dark Energy (Hot NEDE) with Dark Radiation Matter Decoupling (DRMD), also meets the requirements for explaining the DESI results, as shown in the leftmost panel of the figure below. The green curve is the favoured DAO position by the DESI DR2 data on small scales, and the dotted black line is the prediction of DRMD in Hot NEDE, when solving the Hubble tension.

Screenshot 2025-12-19 at 07.52.54.png

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In a new paper “we explore the possibility that exotic forms of dark matter could expose humans on Earth or on prolonged space travel to a significant radiation dose. The radiation exposure from dark matter interacting with nuclei in the human body is generally assumed to be negligible compared to other sources of background radiation. However, as we discuss here, current data allow for dark matter models where this is not necessarily true”. See: https://arxiv.org/abs/2411.10521

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The ESA Euclid experiment will map around a billion galaxies in the next six years and give us new insights into the properties of Dark Matter and Dark Energy. Today, Euclid released its first pictures: Euclid’s first images.

Euclids view of the Perseus cluster of galaxies

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First Sloth in space! Zero-G indicator on today’s mission to the space station was a Sloth 🦥