Dark energy

Blogs about dark energy

Simulation of the large-scale structure of the universe (Image Nico Hamaus, Universit√§ts-Sternwarte M√ľnchen, courtesy of The Ohio State University)

An article accepted for publication in the journal “Physical Review Letters” describes a research on the distribution of matter in the universe made in a way different from usual. An international team of researchers studied cosmic voids as if they were photographic negatives from which they could get information about ordinary matter, dark energy and dark matter.

The galaxy UGC 9391 seen by the Hubble Space Telescope. Cepheid variable are in red circles, a type Ia supernova is marked by a blue cross (Image NASA, ESA, and A. Riess (STScI/JHU))

An article accepted for publication in “The Astrophysical Journal” describes a research based on observations made with the Hubble Space Telescope that suggests that the universe is expanding at a faster rate than expected. A team of astronomers led by Nobel laureate Adam Riess measured the distance of stars in nineteen galaxies with the best accuracy ever achieved to obtain this surprising result.

The Abell 1689 galaxy cluster

An article published in the journal “Physical Review Letters” offers clues about the link between the internal structure of a galaxy cluster and the dark matter environment surrounding it. The study of dark matter is complex because it can only be done indirectly due to the fact that we can’t detect it directly. Until now, scientists believed that the greater the mass of a cluster the greater the amount of dark matter in its environment. This new research suggests that things are more complicated.

Supernova in the galaxy M82 captured by the Swift satellite. Mid-ultraviolet light is shown in blue, near-UV light in green and visible light in red (Image NASA/Swift/P. Brown, TAMU)

A research conducted by a team led by astronomer Peter A. Milne of the University of Arizona published in two articles in the “Astrophysical Journal” shows that Type Ia supernovae can be divided into two groups with different characteristics. For years, astronomers had thought that their brightness depended almost exclusively on their distance. This can have consequences on our knowledge of the universe expansion, also calculated based on this type of supernovae.