WFIRST: The Essential Cosmology Space Observatory for the Coming Decade

TL;DR

WFIRST is a space telescope designed to investigate cosmic acceleration by measuring the universe's expansion and structure growth, aiming to resolve fundamental questions about dark energy and gravity.

Contribution

The paper discusses how WFIRST's mission design enhancements make it a crucial and more capable tool for dark energy research in the coming decade.

Findings

WFIRST's improved design enhances dark energy measurement capabilities.

The mission offers multiple redundant probes for cosmic acceleration.

It is positioned as the essential space-based dark energy observatory for the mid-2020s.

Abstract

Two decades after its discovery, cosmic acceleration remains the most profound mystery in cosmology and arguably in all of physics. Either the Universe is dominated by a form of dark energy with exotic physical properties not predicted by standard model physics, or General Relativity is not an adequate description of gravity over cosmic distances. WFIRST emerged as a top priority of Astro2010 in part because of its ability to address the mystery of cosmic acceleration through both high precision measurements of the cosmic expansion history and the growth of cosmic structures with multiple and redundant probes. We illustrate in this white paper how mission design changes since Astro2010 have made WFIRST an even more powerful dark energy facility and have improved the ability of WFIRST to respond to changes in the experimental landscape. WFIRST is the space-based probe of DE the community needs in the mid-2020s.