Dark Energy from Large-Scale Structure Lensing Information

Understand

Wide area Large-Scale Structure (LSS) surveys are planning to map a substantial fraction of the visible universe to quantify dark energy through Baryon Acoustic Oscillations (BAO).

• At increasing redshift, for example that probed by proposed 21-cm intensity mapping surveys, gravitational lensing potentially limits the fidelity (Hui et al., 2007) because it distorts the apparent matter distribution.
• In this paper we show that these distortions can be reconstructed, and actually used to map the distribution of intervening dark matter.
• The lensing information for sources at z=1-3 allows accurate reconstruction of the gravitational potential on large scales, l <~ 100, which is well matched for Integrated Sachs-Wolfe (ISW) effect measurements of dark energy and its sound speed, and a strong constraint for modified gravity models of dark energy.