Century of $\Lambda$

TL;DR

This paper reviews the century-long history of the cosmological constant, from Einstein's initial proposal to its modern role in explaining the universe's accelerated expansion, highlighting its scientific evolution and unresolved nature.

Contribution

It provides a historical overview of the cosmological constant's development, emphasizing its changing scientific perception over a hundred years.

Findings

The cosmological constant was introduced by Einstein in 1917.

Einstein rejected the cosmological constant in 1931.

Recent observations support the cosmological constant as the cause of accelerated expansion.

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.