LiteBIRD (Lite satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection) is a JAXA’s strategic large mission candidate in Phase-A1 (concept development).

LiteBIRD  has the goal of being a very focused mission to test inflation with all-sky surveys of CMB polarization. Primordial gravitational waves, emitted during the cosmic inflation era (around 10–38 sec after the beginning of the Universe), are expected to be imprinted in the CMB polarization map as special patterns, called the “B-mode”. From the viewpoint of high-energy physics or elementary particle physics, the observation of the CMB B-mode is very important because it will allow us to search for physics in ultra high-energy scales, which are not accessible with man-made accelerators. Measurements of CMB polarization will open a new era of testing theoretical predictions of quantum gravity, including those by the superstring theory.

LiteBIRD was recently nominated one of the 7 large-scale projects in the MEXT 2017 roadmap. Support from NASA has funded detector and cryogenic readout system development in the USA for Phase A, and is now supporting risk-mitigation R&D.

With the LiteBIRD baseline design still under discussion, Europe has an opportunity to provide significant impact on the final payload by delivering the High-Frequency Telescope (HFT) unit.