Fundamental physics from the large-scale structure of the Universe

大爆炸后的第一秒发生了什么？为什么宇宙的膨胀在加速？什么是暗能量？我们的宇宙仍然有许多谜团，从最早的开始到现在的加速膨胀。虽然研究宇宙的起源和演化本身就令人兴奋，但特别驱使我的是宇宙学与基本物理理论的联系。宇宙是最大的实验室，我们必须推动我们对物理定律的理解！虽然早期宇宙的物理学和暗能量的根本原因仍然令人困惑，但可以肯定的是，我们可以通过宇宙中星系的聚集来研究这两者。我的研究重点是分析我们宇宙中星系的大尺度结构，以揭示暗能量的潜在性质，并确定大爆炸后毫秒内驱动宇宙膨胀的物理理论。暗能量光谱仪（DESI）旨在解决这些问题：经过十多年的发展，DESI于2019年实现了第一次光。今年，DESI开始了为期5年的调查，绘制了几乎半个天空中数千万个星系的3D位置。我在攻读博士学位期间加入了DESI，我很高兴看到这个项目从一个纯粹的提议发展到最终开始我的研究，其第一年的数据将对宇宙学和我们对基础物理学的理解产生关键影响。

What happened in the first second after the Big Bang? Why is the expansion of the Universe accelerating? And what is dark energy?Our Universe still holds many mysteries, from its earliest beginnings to its current accelerated expansion. While studying the origin and evolution of our Universe is exciting by itself, what especially drives me is the link of cosmology to fundamental physical theories. The Universe is the largest laboratory we have to push our understanding of the laws of physics!While the physics of the early Universe and the underlying cause of dark energy remains puzzling, what is certain is that we can study both through the clustering of galaxies in our Universe. My research focuses on analysing the large scale structure of galaxies in our Universe to uncover the underlying nature of dark energy and determine the physical theory that drives the expansion of the Universe milli-seconds after the Big Bang.The Dark Energy Spectroscopic Instrument (DESI) is designed to tackle these questions: after more than a decade of development, DESI achieved first light in 2019. This year DESI began its 5-year survey mapping the 3D positions of tens of millions of galaxies across almost half the sky. I joined DESI during my PhD and am excited to see the project evolve from being a mere proposal to finally start my research with its first year of data that will have pivotal impact on cosmology and our understanding of fundamental physics.