Report of the Dark Energy Task Force

TL;DR

This report emphasizes the importance of understanding dark energy, which dominates the universe's composition, and advocates for an ambitious observational program to uncover its properties due to its fundamental scientific significance.

Contribution

It provides a comprehensive overview of dark energy's significance and calls for an extensive observational effort to investigate its nature and properties.

Findings

Dark energy is the dominant component of the universe.

Current theories are insufficient to explain dark energy.

Understanding dark energy may require a revolution in fundamental physics.

Abstract

Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. The acceleration of the Universe is, along with dark matter, the observed phenomenon that most directly demonstrates that our theories of fundamental particles and gravity are either incorrect or incomplete. Most experts believe that nothing short of a revolution in our understanding of fundamental physics will be required to achieve a full understanding of the cosmic acceleration. For these reasons, the nature of dark energy ranks among the very most compelling of all outstanding problems in physical science. These circumstances demand an ambitious observational program to determine the dark energy properties as well as possible.