Seminar:- Testing Inflation and Constraining Cosmology with the Oldest Light
Inflation ─ the leading model for the earliest moments of the time, in which the Universe undergoes a period of rapid, accelerating expansion ─ generically predicts a background of primordial gravitational waves, which generate a B-mode component in the polarization of the Cosmic Microwave Background(CMB). The measurement of such a B-mode signature would lend significant support to the paradigm of inflation. However, observed B modes also contain a component from the gravitational lensing of primordial E modes, which can obscure the measurement of the primordial B modes. the speaker and her collaborator reduce the uncertainties in the B-mode measurement contributed from this lensing component by a technique called ‘delensing’. In this talk, she will show results of the first and only analysis that reduces cosmological parameter uncertainty, in this case the uncertainty on the tensor-to-scalar ratio from the Background Imaging of Cosmic Extragalactic Polarization (BICEP)/Keck experiments, with delensing.
For upcoming analyses, efficient delensing relies on high signal-to-noise measurements of the CMB lensing mass map. Such lensing maps not only will be essential for testing inflation, they will also provide new cosmological information compared to the primary CMB. This is particularly interesting in light of the current tensions between inferred parameter values of the standard cosmological model ΛCDM such as the Hubble parameter using different data sets. She will show the latest state-of-the-art measurement of CMB lensing using data from the South Pole Telescope, its cosmological parameter constraints, and discuss implications for cosmic tensions and the sum of neutrino masses.
時間：2025.01.07(二) 15:30~16:30
地點：香港中文大學 科學館*北座 G25室
講者：Prof. Kimmy WU Wai-Ling 巫惠玲 教授 (The Division of Physics, Mathematics and Astronomy California Institute of Technology, USA)
語言：英語
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【此屬轉載信息，以主事單位發布為準】
*Science Centre
此活動由香港中文大學物理系主辦。
https://wp.phy.cuhk.edu.hk/wp-content/uploads/25-01-07sem-Wu-WLK.pdf
