In the presence of a new generation of largescale structure surveys, this thesis aims to discuss the method to probe the fundamental physics of inflation from galaxy distribution. In particular, the thesis reviews the introduction of the inflation model. The stateoftheart prediction of the initial condition from inflation is computed with the cosmological perturbation theory based on the theory of General Relativity (GR). The thesis focuses on two fundamental features. Firstly, NonGaussianity (NG) is discussed as an indicator of physics beyond the freesinglescalar field model. Observationally, NG is realized by the nonzero bispectrum of the primordial conserved curvature perturbation. The local, equilateral, enfolded and orthogonal types of bispectrum are introduced with the associated inflation models and their mode dependence. Secondly, the parity symmetry is recognized as a fundamental discrete symmetry of the standard GR, hence the property that one would expect from the observational consequence of inflation. Essentially, the reflection of space should not alter the mechanism generating perturbations during inflation. The thesis then discusses the theory of LSS distribution, particularly how the fluctuation from inflation evolves throughout different epochs. Standard Perturbation Theory (SPT) density perturbation is employed as a method to solve the nonlinear evolution of matter fluid. The theory of biased tracer is introduced as a description of the galaxy population. The tracer number density contrast is written as an expansion of bias parameters and their corresponding physical operators representing the quantity that affects the population. This thesis shows how the list of operators up to the third order is inferred from the gravitational evolution of the tracer. The relation between the statistics of tracers as discrete objects and the statistics of continuous density field are also discussed. With this complete connection from the essence of inflation to observable LSS, the prediction of the tracer's statistics and the bias parameter can be established. The thesis reviews how the NG from inflation introduce some scale dependence to the dark matter (DM) halo bias parameter. In particular, the MatarreseLucchinBonometto (MLB) approach is reviewed. The thesis discusses the formation theory of DM halo as a virialized object enclosing smaller structure clusters of galaxies. As its position can be inferred from the clustering of galaxies, the statistics can be probed from which the bias parameters can be inferred. Therefore, such measurement can be used to constrain the level of NG in the initial condition. The dependence on the sample's halo mass and the window function based on the MLB approach is also illustrated. Lastly, the parity violation (PV) of the galaxy's fourpoint correlation (4PCF) function is considered. In the presence of two independent analyses (J.Hou et al. 2023 and O.H.E.Philcox 2022) findings, this thesis assesses whether the redshift space distortion (RSD) effect can mimic the PV in the observed 4PCF. While the parityodd mode of trispectrum (the Fouriercounterpart of 4PCF) has been studied in the literature (P.Paul et al. 2024), this thesis extends the result by considering the wideangle effect and properly correcting the local lineofsight (LOS) for each galaxy with Taylor's expansion. It is shown in this thesis that the averaging over survey volume completely removes the PV introduced by RSD, suggesting that the isotropic 4PCF estimator used in J.Hou et al. 2023 and O.H.E.Philcox 2022 are free of such contamination. Some fundamental sources of PV and caveats are commented on.
In the presence of a new generation of largescale structure surveys, this thesis aims to discuss the method to probe the fundamental physics of inflation from galaxy distribution. In particular, the thesis reviews the introduction of the inflation model. The stateoftheart prediction of the initial condition from inflation is computed with the cosmological perturbation theory based on the theory of General Relativity (GR). The thesis focuses on two fundamental features. Firstly, NonGaussianity (NG) is discussed as an indicator of physics beyond the freesinglescalar field model. Observationally, NG is realized by the nonzero bispectrum of the primordial conserved curvature perturbation. The local, equilateral, enfolded and orthogonal types of bispectrum are introduced with the associated inflation models and their mode dependence. Secondly, the parity symmetry is recognized as a fundamental discrete symmetry of the standard GR, hence the property that one would expect from the observational consequence of inflation. Essentially, the reflection of space should not alter the mechanism generating perturbations during inflation. The thesis then discusses the theory of LSS distribution, particularly how the fluctuation from inflation evolves throughout different epochs. Standard Perturbation Theory (SPT) density perturbation is employed as a method to solve the nonlinear evolution of matter fluid. The theory of biased tracer is introduced as a description of the galaxy population. The tracer number density contrast is written as an expansion of bias parameters and their corresponding physical operators representing the quantity that affects the population. This thesis shows how the list of operators up to the third order is inferred from the gravitational evolution of the tracer. The relation between the statistics of tracers as discrete objects and the statistics of continuous density field are also discussed. With this complete connection from the essence of inflation to observable LSS, the prediction of the tracer's statistics and the bias parameter can be established. The thesis reviews how the NG from inflation introduce some scale dependence to the dark matter (DM) halo bias parameter. In particular, the MatarreseLucchinBonometto (MLB) approach is reviewed. The thesis discusses the formation theory of DM halo as a virialized object enclosing smaller structure clusters of galaxies. As its position can be inferred from the clustering of galaxies, the statistics can be probed from which the bias parameters can be inferred. Therefore, such measurement can be used to constrain the level of NG in the initial condition. The dependence on the sample's halo mass and the window function based on the MLB approach is also illustrated. Lastly, the parity violation (PV) of the galaxy's fourpoint correlation (4PCF) function is considered. In the presence of two independent analyses (J.Hou et al. 2023 and O.H.E.Philcox 2022) findings, this thesis assesses whether the redshift space distortion (RSD) effect can mimic the PV in the observed 4PCF. While the parityodd mode of trispectrum (the Fouriercounterpart of 4PCF) has been studied in the literature (P.Paul et al. 2024), this thesis extends the result by considering the wideangle effect and properly correcting the local lineofsight (LOS) for each galaxy with Taylor's expansion. It is shown in this thesis that the averaging over survey volume completely removes the PV introduced by RSD, suggesting that the isotropic 4PCF estimator used in J.Hou et al. 2023 and O.H.E.Philcox 2022 are free of such contamination. Some fundamental sources of PV and caveats are commented on.
Probing Fundamental Physics With Galaxy Biasing
KONGPRACHAYA, CHANASORN
2023/2024
Abstract
In the presence of a new generation of largescale structure surveys, this thesis aims to discuss the method to probe the fundamental physics of inflation from galaxy distribution. In particular, the thesis reviews the introduction of the inflation model. The stateoftheart prediction of the initial condition from inflation is computed with the cosmological perturbation theory based on the theory of General Relativity (GR). The thesis focuses on two fundamental features. Firstly, NonGaussianity (NG) is discussed as an indicator of physics beyond the freesinglescalar field model. Observationally, NG is realized by the nonzero bispectrum of the primordial conserved curvature perturbation. The local, equilateral, enfolded and orthogonal types of bispectrum are introduced with the associated inflation models and their mode dependence. Secondly, the parity symmetry is recognized as a fundamental discrete symmetry of the standard GR, hence the property that one would expect from the observational consequence of inflation. Essentially, the reflection of space should not alter the mechanism generating perturbations during inflation. The thesis then discusses the theory of LSS distribution, particularly how the fluctuation from inflation evolves throughout different epochs. Standard Perturbation Theory (SPT) density perturbation is employed as a method to solve the nonlinear evolution of matter fluid. The theory of biased tracer is introduced as a description of the galaxy population. The tracer number density contrast is written as an expansion of bias parameters and their corresponding physical operators representing the quantity that affects the population. This thesis shows how the list of operators up to the third order is inferred from the gravitational evolution of the tracer. The relation between the statistics of tracers as discrete objects and the statistics of continuous density field are also discussed. With this complete connection from the essence of inflation to observable LSS, the prediction of the tracer's statistics and the bias parameter can be established. The thesis reviews how the NG from inflation introduce some scale dependence to the dark matter (DM) halo bias parameter. In particular, the MatarreseLucchinBonometto (MLB) approach is reviewed. The thesis discusses the formation theory of DM halo as a virialized object enclosing smaller structure clusters of galaxies. As its position can be inferred from the clustering of galaxies, the statistics can be probed from which the bias parameters can be inferred. Therefore, such measurement can be used to constrain the level of NG in the initial condition. The dependence on the sample's halo mass and the window function based on the MLB approach is also illustrated. Lastly, the parity violation (PV) of the galaxy's fourpoint correlation (4PCF) function is considered. In the presence of two independent analyses (J.Hou et al. 2023 and O.H.E.Philcox 2022) findings, this thesis assesses whether the redshift space distortion (RSD) effect can mimic the PV in the observed 4PCF. While the parityodd mode of trispectrum (the Fouriercounterpart of 4PCF) has been studied in the literature (P.Paul et al. 2024), this thesis extends the result by considering the wideangle effect and properly correcting the local lineofsight (LOS) for each galaxy with Taylor's expansion. It is shown in this thesis that the averaging over survey volume completely removes the PV introduced by RSD, suggesting that the isotropic 4PCF estimator used in J.Hou et al. 2023 and O.H.E.Philcox 2022 are free of such contamination. Some fundamental sources of PV and caveats are commented on.File  Dimensione  Formato  

KONGPRACHAYA_CHANASORN.pdf
accesso aperto
Dimensione
4.32 MB
Formato
Adobe PDF

4.32 MB  Adobe PDF  Visualizza/Apri 
The text of this website © Università degli studi di Padova. Full Text are published under a nonexclusive license. Metadata are under a CC0 License
https://hdl.handle.net/20.500.12608/71370