On April 19, the research team from the Galaxy Survey Cosmology Research Group at the National Astronomical Observatory of the Chinese Academy of Sciences (hereafter referred to as the National Astronomical Observatory), in collaboration with international peers, published a new research paper in "Communications Physics." Researchers have developed a new method to extract multi-point correlation functions from the two-point correlation functions of galaxies. This achievement offers a new approach for conducting cutting-edge cosmological research in the next generation of large-scale galaxy surveys.
Research Illustration. Image provided by the research team.
In the current era of precision cosmology, large-scale galaxy redshift surveys serve as powerful tools for exploring the universe. By measuring the spectra of a vast number of distant celestial objects, scientists can utilize redshift surveys to obtain density fields of the universe at different evolutionary stages. The galaxy density field contains crucial information about the clustering of galaxies, manifested particularly in the two-point and multi-point correlation functions of galaxies.
The multi-point correlation function of galaxies complements the two-point correlation function significantly and is crucial for studying dark energy, dark matter, and gravitational properties. However, due to the complexity of the multi-point correlation function, both its measurement and modeling pose considerable challenges, resulting in bottlenecks in cosmological applications.
To address this, the research team at the National Astronomical Observatory of China, in collaboration with international peers, has developed a novel method for extracting multi-point correlation functions from the two-point correlation function of galaxies after years of in-depth cooperation and research.
In their latest paper, the scientists, leveraging galaxy density field reconstruction techniques, accurately and efficiently extracted much of the information pertaining to three-point and four-point correlation functions by organically combining the density fields before and after reconstruction.
The researchers state that this achievement will provide new avenues for conducting cutting-edge cosmological research with next-generation large-scale galaxy surveys such as the Dark Energy Spectroscopic Instrument (DESI), the Prime Focus Spectrograph (PFS), and sky surveys from the Chinese space station.
Related paper: https://doi.org/10.1038/s42005-024-01624-7
