Century of Λ

Abstract

The cosmological constant was proposed 100 years ago in order to make the model of static Universe, imagined then by most scientists, possible. Today it is the main candidate for the physical essence causing the observed accelerated expansion of our Universe. But, as well as a hundred years ago, its nature is unknown. This paper is devoted to the story of invention of $\Lambda$ by Albert Einstein in 1917, rejection of it by him in 1931 and returning of it into the science by other scientists during the century.