Scientists have detected an anomalous increase in the expansion rate of the Universe

New data on nearby galaxies showed a local increase in the Hubble constant, a value that indicates the speed of the expansion of galaxies in the Universe and its expansion. There is already something wrong with the Hubble constant, since it has one value at the dawn of the Universe and another in our region of space. To explain this, the concept of Hubble tension is introduced. The latest work from scientists shows that this difference may be even stronger, and the Universe is expanding faster than expected.

Coma Cluster. Image source: CTIO/NOIRLab/DOE/NSF/AURA

In the Universe it is quite difficult to determine the distance to the object being studied. In this case, all measurements must be correlated with Einstein’s equations about the behavior of space-time. However, scientists have found ways to circumvent these difficulties by using unique beacons in the form of supernovae, red giants, Cepheids and other stars, the brightness and spectra of which are the same anywhere in the Universe. Based on data on beacon stars, the Hubble constant is 73.24 ± 1.74 (km/s)/Mpc. But there is also cosmic microwave background radiation and the LambdaCDM model based on it, which give a value of the Hubble constant of 66.93 ± 0.62 (km/s)/Mpc. The difference between these measurements and calculations is called the Hubble intensity.

About a year ago, the DESI (Dark Energy Spectroscopic Instrument) instrument completed its first survey of the sky. It collects spectra of galaxies (and quasars) down to depths of up to 11 billion years to estimate the true distances between galaxies and try to create fundamental physical constraints on the study of dark energy. The same data is suitable for other studies – from confirming Einstein’s general relativity to searching for problems with the Hubble constant.

A team of scientists from Duke University, led by physicist Dan Scolnic, used data from the first year of DESI observations to estimate the distance to the Coma cluster, which is about 320 million light-years away. Using data from 13 Type Ia supernovae, the team calculated that the cluster is 321 million light years away, which may be the best estimate to date. This gave a value for the Hubble constant of 76.5 ± 2.2 (km/s)/Mpc. It is easy to see that this is higher than previous estimates for our region of space.

Since the Hubble constant estimate was made for one star cluster, scientists called the discovered anomaly in the Hubble intensity local, but did not rule out that the Hubble constant could be even stronger than commonly believed. This increases the crisis in cosmology and makes us think that there may be something wrong with our theories and models.