Who am I?

I am Jiazheng Dou, a final year PhD student in Department of Astronomy at University of Science and Technology of China (USTC), focusing on cosmology of cosmic microwave background (CMB) observations. Currently I’m seeking for the postdoctoral positions starting 2025 fall.

Over the past three decades, measurements of the CMB temperature anisotropies and E-mode polarization by WMAP and Planck satellites, along with sub-orbital experiments like SPT and ACT, have led to high-precision estimation of cosmological parameters in the ΛCDM model. A primary goal for current and forthcoming CMB experiments is the detection of primordial gravitational waves (PGWs) through their imprint on the CMB B-mode polarization.

Since PGWs are extremely faint, various contaminants, including the dominant polarized foregrounds (e.g., Galactic dust and synchrotron), the instrumental noise, the B modes generated from E modes (i.e. E-to-B leakage, such as lensing B modes), and complicated systematics, limit the precision of the CMB B-mode estimation, making it a very challenging task to detect the PGWs. The high-precision measurements of astrophysical components (i.e. component separation) and the calibration of systematics, might impede each other through biases in parameter estimation. One of my tasks is to robustly extract the B-mode signal from CMB observations against various sky components and systematic effects.

During my PhD, I was responsible for constructing the component separation, power spectrum estimation, and cosmological parameter estimation pipeline for the Ali CMB Polarization Telescope (AliCPT) collaboration. In my publications, I forecast the foreground cleaning performance of various Internal Linear Combination (ILC) methods on the AliCPT simulations, and validated the use of the systematic mitigation pipeline such as deprojection.