The Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, uses the "Subaru Telescope" to measure the distance of galaxies in the distant universe to explore the mystery of the accelerated expansion of the universe. Was created and its growth rate was measured successfully for the first time in the world.This is due to international research conducted mainly by Kavli IPMU at the University of Tokyo, Tohoku University, etc., and was published in the online version of the Journal of the Astronomical Society of Japan, "Publications of the Astronomical Society of Japan".
The universe has been expanding since the Big Bang.In theory, the expansion should slow down, but it is known that it is accelerating and expanding.It is possible that the "general theory of relativity" on which cosmology is based has collapsed as the cause, but it has not been clarified.
Einstein's theory of gravity "general relativity" can be tested by measuring the distance to the galaxy and examining the three-dimensional distribution of the galaxy in the universe, which is relatively close to about 3 billion light-years. Limited to space.
This time, the research group used the galaxy survey "FastSound" to measure the distances to about 130 galaxies at an average distance of 3000 billion light-years, and completed a large-scale three-dimensional structure map.We also investigated the movement of galaxies on the map in detail and succeeded in measuring the growth rate with a high significance of 3%.He also confirmed that the growth rate matches the prediction of the general theory of relativity within the range of measurement error.
Einstein once added a "cosmological constant" to the general theory of relativity to insist that "the size of the universe does not change," but withdrew it when Hubble discovered the expansion of the universe.However, the current accelerating expansion universe can be explained by adding the cosmological constant to the general theory of relativity, and this observation supports this model.
On the other hand, the physical origin of the cosmological constant remains a mystery.Based on this result, it is expected that the new observation device currently under development will produce further global results.