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Systematics Study and Detection of Baryon Acoustic Oscillations from Future Galaxy Survey and Weak Lensing Survey

Ding, Zhejie
http://orcid.org/0000-0002-3369-3718
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1554330484538948

Abstract Details

2019, Doctor of Philosophy (PhD), Ohio University, Physics and Astronomy (Arts and Sciences).
The scale of Baryon Acoustic Oscillations (BAO) is an important standard ruler to measure the expansion history of the Universe in modern cosmology. Ongoing and future large-scale surveys will dramatically decrease the statistic error of the BAO scale to tenths of a percent level, which demands the control of systematic error equal or below sub-percent level. In our first project, we modeled the systematics effects on the BAO feature from non-linear structure growth, redshift-space distortions, and galaxy/halo bias, theoretically as well as numerically. We used mock catalogues of matter and galaxy from the quasi-N-body FastPM simulation, and investigated such effects over a wide range of redshifts, galaxy/halo biases and shot noise levels. We applied a new BAO fitting model (EFT) and tested it based on the precision of measuring the BAO scale and other non BAO parameters, such as the structure growth rate and the nonlinear galaxy bias. We compared the result with that from the nominal BAO fitting model. We also compared the systemtics of the BAO scale from catalogues before and after density field reconstruction, and tested different reconstruction schemes. For pre-reconstruction, the BAO scale measurement has $0.07\%$ fitting-model dependence for galaxy power spectrum, which is smaller than that of matter with $0.1\%-0.2\%$. For post reconstruction (with the default scheme), the systematic error of the BAO scale measurement is generally less than $0.1\%$ for both galaxy and matter power spectrum, and has much lower fitting model dependence. Different reconstruction schemes can generate as large as $0.3\%$ difference when measuring the BAO scale along the line of sight. However, the measurement precision on the BAO scale varies little from the fitting models or the reconstruction schemes. We suggested similar analysis can be conducted using the full N-body simulations. Further work on reconstruction schemes or post reconstruction BAO fitting models may be necessary to obtain the non-BAO information precisely. In the second project, we extended the BAO scale detection from galaxy surveys to weak lensing surveys, and investigated the feasibility of extracting the BAO scale directly from cosmic shear tomography. We particularly focused on the precision of the BAO scale measurement from the spectroscopy-based, kinematic weak lensing (KWL) surveys \citep[e.g.,][]{Huff13} in comparison to the traditional photometric weak lensing (PWL) surveys. Shape noise is smaller and redshift measurement of source galaxies is more precise in KWL surveys. Taking these into account and using the Limber approximation, we simulated shear power spectrum with and without the BAO signature for the two types of surveys. We constructed the Gaussian covariance matrix of shear power spectrum with shape noise included. We used $\chi^2$ analysis and singular value decomposition to extract the matter power spectrum from the simulated shear data. Using the BAO fitting model to fit the isolated BAO signature from the extracted power spectrum, we obtained the systematic error and the significance level of the BAO scale detection. We predicted that the Dark Energy Task Force Stage IV KWL survey can detect the BAO scale with $4\%$ precision and $3\sigma$ significance, compared to the insignificant detection level from the PWL-Stage IV survey. Decreasing shape noise can improve the detection level for both PWL and KWL. A built-in spectroscopic galaxy survey within the KWL survey can allow a cross-correlation between the BAO scale from galaxy clustering and cosmic shear, and tighten the precision of measurement. It can also help to derive the BAO scale bias between galaxies and dark matter.
Hee-Jong Seo (Advisor)
Douglas Clowe (Committee Member)
Charlotte Elster (Committee Member)
Smoki Musaraj (Committee Member)
180 p.
Astrophysics
large-scale structure of universe; baryon acoustic oscillations; cosmological parameters; simulation; gravitational weak lensing; theory

Recommended Citations

Citations

  • Ding, Z. (2019). Systematics Study and Detection of Baryon Acoustic Oscillations from Future Galaxy Survey and Weak Lensing Survey [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1554330484538948

    APA Style (7th edition)

  • Ding, Zhejie. Systematics Study and Detection of Baryon Acoustic Oscillations from Future Galaxy Survey and Weak Lensing Survey. 2019. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1554330484538948.

    MLA Style (8th edition)

  • Ding, Zhejie. "Systematics Study and Detection of Baryon Acoustic Oscillations from Future Galaxy Survey and Weak Lensing Survey." Doctoral dissertation, Ohio University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1554330484538948

    Chicago Manual of Style (17th edition)

ohiou1554330484538948
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This open access ETD is published by Ohio University and OhioLINK.