Influence Of Cosmic Turbulence On The Deviation Between Baryonic Field And Dark Matter Field

Theoretical studies and some observations show that the cosmic baryonic fluid at low redshifts is similar to the fully developed turbulence.This situation has led to a growing view that turbulence should be an essential part of baryonic physics.In this paper,by using the data from cosmological numerical simulations,we analyze the effect of turbulence-induced deviation between baryonic field and dark matter field in the spatial distribution of the universe.In the first chapter,we briefly introduce the deviation between the baryonic field and dark matter field in the spatial distribution of the universe and the role of turbulence in it to clarify the significance of cosmic turbulence.In the second chapter,we make a crucial summary of the theory involved in this paper.This includes not only the theoretical basis of cosmology such as cosmological principle,Friedmann equation,component of the universe,etc.but also theories related to turbulence such as Reynolds experiment,Navier-Stokes equations,Kolmogorov turbulence theory,etc.The third chapter introduces the commonly used dark matter numerical simulation algorithms and hydrodynamic numerical simulation algorithms in cosmology numerical simulation programs.It also introduces the specific implementation steps of the PM dark matter numerical simulation algorithm and WENO hydrodynamic numerical simulation algorithm used in the WIGEON simulation program.It also includes our derivation results for higher-precision PM dark matter numerical simulation algorithms.Chapter 4 uses simulation data generated by the hybrid cosmological hydrodynamical/N-body code WIGEON and Illustris TNG to explore the effect of turbulence-induced deviation between the baryonic field and dark matter field in the spatial distribution of the universe,which is also the most innovative part of this paper.We analyze the scale dependence of baryon-dark deviation by calculating the cross-correlation function of the density and velocity fields of the two components.We also analyze environment-dependent deviation between baryonic field and dark matter field in the spatial distribution of the universe by dividing the cosmic web into different structures.Baryonic physical processes such as star formation,SN,and AGN feedback are not included in WIGEON simulations.Therefore,by comparing these results with Illustris TNG simulations,we analyze how turbulence-induced deviation compared to other baryonic processes.Chapter 5 summarises the results obtained in this paper and looks forward to future research on cosmic turbulence.