学术报告—Weak Lensing and Precision Cosmology

Abstract: 

Weak lensing has emerged as a powerful tool to probe cosmology. It can provide independent constrains of cosmological parameters which could potentially help solve some of the challenges faced by the ΛCDM model, such as the  and  tensions. However, weak lensing measurements of the cosmic shear are complex, and exhaustive treatments of all possible source of systematics are needed.

Fourier_Quad is a unique shear measurement pipeline that works on the power spectrum of galaxy images. It performs background removal, defects detection, source identification, astrometric calibration, PSF reconstruction, and shear measurement. It has proven to be extremely fast and been able to achieve sub-percent accuracy.

Recently, we have developed a new PSF reconstruction that can outperform our previous PSF interpolation. We have also developed a new method to detect anomalous images. In addition, using the Fourier_Quad pipeline we have performed a comparative study of the observational and simulation results on galaxy-galaxy lensing.

Bio:

Pedro Alonso’s research interests include Weak Lensing and applications of Machine Learning in Astronomy.  In 2016, he obtained his Bachelor’s degree in physics at the University of Zaragoza, Spain. In 2018 he received his master’s degree in physics and mathematics (theoretical physics specialization) at the University of Salamanca, Spain. In 2019, he began his Ph.D studies in Astronomy at Shanghai JiaoTong University, China.