We now know that the Universe started with a hot Big Bang; that it underwent a period called the Dark Ages without light; that the first stars formed about 200 million years later; that it was fully reionized within the first billion years; and that the peak of galaxy formation took place 2-3 billion years after the Big Bang.
A main reason we know all these things is the Cosmic Microwave Background (CMB), which is left-over heat radiation from the Big Bang itself.
The next frontier in CMB science is polarization measurements, and the main scientific motivation for measuring this signal is to constrain the Big Bang phase itself. According to current inflationary theories, all scales in the universe expanded from sub-atomic to galactic scales during a tiny fraction of a second, and this process created the seeds of all structures we observe today. Additionally, the same theories also predict that there should exist a background of primordial gravitational waves that stretched and squeezed space itself. And this massaging of space should be observable in the form of large-scale CMB B-mode polarization today. This signal is so important that the first group to unambiguously measure this signal will very likely be awarded the Nobel prize in physics.
LiteBIRD
LiteBIRD (Lite (Light) satellite for the studies of B-mode polarization and Inflation from the cosmic background Radiation Detection) is a CMB polarization satellite experiment scheduled to be launched in the early 2030’s. The main goal is to measure or constrain large-scale primordial gravitational waves through the B-modes in the CMB, and thereby constrain theories of inflation in the early Universe.
Recognizing the leading role of the Norwegian CMB community, Prof. Masashi Hazumi (LiteBIRD PI) invited the University of Oslo into the LiteBIRD collaboration in 2016 (which, in fact, is earlier than most other European groups), and has been an active member ever since. Originally, this work was supported between 2016 and 2020 by an RCN ROMFORSK grant (PI: Prof. Ingunn Kathrine Wehus; grant no. 263011), and later indirectly by two ERC grants (bits2cosmology led by Prof. Eriksen and Cosmoglobe by Prof. Wehus). Based on this work, the Norwegian CMB group has established itself as a key player in the LiteBIRD collaboration.
Read more about LiteBIRD project
In this follow up project, we aim at establishing a dedicated LiteBIRD Data Processing Center at the University of Oslo (LDPC-Norway), taking full advantage of our world-leading expertise in computational CMB analysis.
The current project will cover the prelaunch, commissioning and early data taking period from 2025 to 2033.
Objectives
Given this general background, we are ready to summarize the main objectives of the project:
1. Establish a LiteBIRD data processing center dedicated to global Bayesian end-to-end analysis at the University of Oslo.
2. Provide HPC resources with fast data access to the entire LiteBIRD collaboration.
3. Establish a functional end-to-end analysis pipeline for LiteBIRD data, both for a stand-alone data set and together with external data from Planck, WMAP and other experiments.
4. Produce and distribute realistic LiteBIRD simulations, and use these to forecast and optimize the experiment and analysis pipeline prior to launch.
5. Perform quick-look analysis of the real LiteBIRD data during commissioning.
6. Analyze the first year of LiteBIRD data.
While most, if not all, of these goals appear practical in nature, it is important to stress that their fundamental long-term aim is truly spectacular: To understand the physical processes that created the Universe itself, and possibly make the world’s first image of gravitational waves from the Big Bang.
