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2025.04.21

Clustering analysis on 4MOST Cosmology Redshift survey

<p>This presentation is divided into three main parts:Overview of Large-Scale Structure (LSS) Studies in CosmologyThis section introduces the theoretical framework behind the formation and evolution of large-scale structure, observations on LSS, statistical techniques used for LSS data analysis, and key phenomena (BAO, RSD and AP effect) associated with LSS.Introduction to 4MOST and the Cosmologic...</p>

2025.04.16

基于宇宙微波背景与射电观测的宇宙学研究

<p>通过联合宇宙微波背景和射电波段的观测可以揭示宇宙从早期到晚期不同阶段的演化历史。未来对宇宙微波背景偏振信号的高精度测量，将有助于探测由主要扰动及次级效应产生的新偏振信号，为早期宇宙物理机制及大尺度结构的形成与演化提供重要观测依据。同时，中性氢21厘米线信号可在不同红移和空间尺度上追踪暗物质主导的大尺度结构，为暗物质和暗能量的研究提供重要线索。宇宙微波背景与21厘米线信号在时间和空间尺度上的互补性，...</p>

2025.03.06

Galaxy quenching from the perspective of semi-analytic model GAEA [EN]

<p>Galaxy quenching is a crucial phase of galaxy evolution. For years the over-quenching problem has posed a big challenge to galaxy evolution models at low redshift. In this talk, I will introduce how we improve the semi-analytic model GAEA step-by-step to reproduce the observed quenched fractions, and the lessons we learned. Then we apply this model to high redshift to understand the galaxy quen...</p>

2025.02.18

面向天文观测和深空探测的光电探测技术 [中文报告]

<p>天文及深空科学是主要由实测驱动的学科。观测设备的实测精度和能力的显著提高会大大促进人类对宇宙的认知，包括21世纪所面临的几个重大挑战包括暗物质、暗能量研究，高红移宇宙，以及外行星和生命起源。这些重大科学问题的攻克、前沿研究的突破性进展，已经越来越依赖于观测设备能力的不断提升，包括提高观测的灵敏度、谱分辨率、时间分辨率、角分辨率以及拓展波段覆盖区域。这些观测设备就需要功能强大性能卓越的焦面仪器系统...</p>

2025.03.06

Galaxy quenching from the perspective of semi-analytic model GAEA

<p>Galaxy quenching is a crucial phase of galaxy evolution. For years the over-quenching problem has posed a big challenge to galaxy evolution models at low redshift. In this talk, I will introduce how we improve the semi-analytic model GAEA step-by-step to reproduce the observed quenched fractions, and the lessons we learned. Then we apply this model to high redshift to understand the galaxy quen...</p>

2025.01.06

Decoding binary neutron stars with the next-generation gravitational wave detectors: localization, parameter estimation, and equations of state

<p>Gravitational waves (GWs) from binary neutron stars (BNSs) offer valuable understanding of the nature of compact objects and hadronic matter. However, the analyses accompanied require massive computational power due to the difficulties in Bayesian stochastic sampling. The third-generation (3G) GW detectors are expected to detect BNS signals with significantly extended signal duration, detection...</p>

2024.12.24

Uncovering Early Galaxy Formation with JWST: A Modeling Perspective

<p>The James Webb Space Telescope (JWST) is transforming our understanding on galaxy formation and evolution, revealing distant galaxies deep into the epoch of reionization and uncovering red sources that were simply unknown pre-JWST. In this talk, I will discuss two key areas, with a focus on the challenges in modeling the spectral energy distributions in the JWST era. First, a central science go...</p>

2024.11.21

On the Formation, Evolution and the Environment of Low Surface Brightness Galaxies [EN]

<p>The variations in the size of galaxies, and consequently, the formation of Low Surface Brighntess Galaxies (LSBGs) could be followed from one of two different effects: variations in the spin parameter of the halo (λ) or variations in the density of dark matter halos (McGaugh 2021). We test both scenarios by employing a simulated sample of galaxies drawn from the TNG100 run of the IllustrisTNG ...</p>

2024.11.20

[PDS seminar] The instability mechanism of compact multiplanet systems [EN]

<p>Numerical integrations of Kepler-like tightly packed planetary systems show that they are chaotic, with fairly short Lyapunov times, but that they can be stable against planet-planet or planet-star collisions for billions of years. Recent work by Petit et al. showed that this behavior was due to the overlap of three-body mean motion resonances. Caleb Lammers, Sam Hadden and I recently showed th...</p>

2024.10.22

Mapping the 3D Universe: From the Past to the Future, Bridging Theories and Observations

<p>This collaborative talk introduces the recent work in COSMO-3D group at EPFL’s Laboratory of Astrophysics (LASTRO). Jiaxi Yu (PhD student) will begin with a historical review of cosmology. The Universe started from a Big Bang, followed by inflation. The emission of the first light of the Universe, cosmic microwave background (CMB), happened in an opaque and dark era of the Universe afterwards....</p>