Year: 2021
Type: article
Abstract: A total of 80% of the matter in the universe is in the form of dark matter that composes the skeleton of the large-scale structure called the cosmic web. As the cosmic web dictates the motion of all matter in galaxies and intergalactic media through gravity, knowing the distribution of dark matter is essential for studying the large-scale structure. However, the cosmic web’s detailed structure is unknown because it is dominated by dark matter and warm−hot intergalactic media, both of which are hard to trace. Here we show that we can reconstruct the cosmic web from the galaxy distribution using the convolutional-neural-network-based deep-learning algorithm. We find the mapping between the position and velocity of galaxies and the cosmic web using the results of the state-of-the-art cosmological galaxy simulations of Illustris-TNG. We confirm the mapping by applying it to the EAGLE simulation. Finally, using the local galaxy sample from Cosmicflows-3, we find the dark matter map in the local universe. We anticipate that the local dark matter map will illuminate the studies of the nature of dark matter and the formation and evolution of the Local Group. High-resolution simulations and precise distance measurements to local galaxies will improve the accuracy of the dark matter map.
Source: The Astrophysical Journal
Authors: Sungwook E. 성욱 Hong 홍, Donghui Jeong, Ho Seong Hwang, Juhan Kim
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G2539654950, G263524748, Cosmology with the galaxy bispectrum: galaxy bias, redshift-space distortion, and primordial non-Gaussianity, WE PROPOSE A RESEARCH PROGRAM THE AIMING AT EXPLOITING THE DATASET FROM THE UPCOMING SPACE MISSIONS: SPHEREX WFIRST AND EUCLID. IN PARTICULAR WE WILL STUDY THE TWO OBSERVABLES THAT ARE NOT PARTS OF THE CURRENT COSMOLOGICAL ANALYSIS: 1) THE GALAXY THREEPOINT CORRELATION FUNCTION AND 2) CLUSTERING FOSSILS. EXPLOITING THE GALAXY THREE-POINT CORRELATION FUNCTION (3PCF) WILL IMPROVE THE DARK ENERGY CONSTRAINT (BOTH GEOMETRICAL AND DYNAMICAL) BY A FACTOR OF TWO COMPARED TO THE CONVENTIONAL ANALYSIS USING ONLY THE TWO-POINT CORRELATION FUNCTION. THE CLUSTERING FOSSILS MEASUREMENT CAN POTENTIALLY BE A POWERFUL TEST OF INFLATIONARY THEORY BY SEARCHING FOR SIGNATURES OF SPECTATOR FIELDS WITH GENERAL-SPIN (THIS INCLUDES THE PRIMORDIAL GRAVITATIONAL WAVES) THAT MIGHT HAVE EXISTED IN THE EARLY UNIVERSE. BY USING THE ANALYTICAL THEORY BASED ON THE GENERAL THEORY OF RELATIVITY AS WELL AS RECENTLY DEVELOPED TOTAL ANGULAR MOMENTUM WAVE METHOD WE PLAN TO INCORPORATE THE RELATIVISTIC PROJECTION EFFECT AS WELL AS WIDE-ANGLE EFFECT. FOR BOTH OBSERVABLES THE KEY THEORETICAL CHALLENGE IS TO MODEL THE COUPLING BETWEEN LONG-WAVELENGTH MODES AND SHORT-WAVELENGTH MODES. WE PLAN TO DEVELOP A THEORETICAL MODEL BY USING THE PERTURBATION THEORY TECHNIQUES AND COMPARE THE VALIDITY OF THE MODELS AGAINST COSMOLOGICAL N-BODY SIMULATIONS. PARALLEL TO THE THEORETICAL STUDIES WE ALSO PLAN TO STUDY THE METHOD TO IDENTIFYING AND MODELING THE SURVEY SYSTEMATICS INDUCED BY DUST CONTAMINATION BRIGHT STARS AS WELL AS OVERLAPPING SPECTRA. FOR THIS STUDY WE SHALL GENERATE THE LOG-NORMAL MOCK CATALOGUES FOR WHICH WE KNOW COMPLETE UNDERLYING STATISTICS. AS AN END PRODUCT OF THE RESEARCH PROGRAM WE WILL HAVE AN END-TO-END DATA ANALYSIS TOOLKIT FOR THE GALAXY 3PCF AND CLUSTERING FOSSILS. THE TOOLKITS INCLUDE FROM THE OPTIMAL ESTIMATOR OF THE SIGNATURE TO ACCURATE THEORETICAL TEMPLATE FOR THE COSMOLOGICAL INTERPRETATION., G7162220615
OpenAlex ID: W3135976083