发布日期：2026-03-10
点击次数：
标题：Atoms, Grains, Infinity: Consistent update the understandings of dust grain physics in diffuse matter astrophysics
时间：2026-04-16, 15:00
主讲人：Lile Wang 王力乐 (PKU)
地点：Physics Building E100
报告语言：English
办公室：E306
Dust grains are fundamental constituents of diffuse matter throughout the universe, mediating key processes from interstellar chemistry to planet formation. Yet their microscopic behaviors, presumably governed by interactions at surfaces, has traditionally been treated through empirical and semi-quantitative prescriptions in most astrophysical models. In this report, we present a series of bottom‑up studies that combine density functional theory (DFT) and DFT‑based machine learning force fields to investigate dust grain physics from first principles. Our results demonstrate that non‑equilibrium kinetics is essential for shaping dust behavior, controlling both the sublimation of the grains themselves and the desorption of volatile species adsorbed on their surfaces. This kinetic nature leads to path‑dependent evolutionary consequences for dust in protoplanetary disks, with prospective implications for observations of thermodynamic signatures, including the locations of disk snowlines and near‑infrared excess. By further incorporating path‑integral Monte Carlo methods, we quantitatively examine nuclear quantum effects in the catalytic formation of molecular hydrogen on dust grain surfaces. We find that quantum tunneling enables efficient molecular hydrogen production across the wide temperature range identified by existing observations. Together, these studies establish a foundation for predictive models of dust physics and chemistry, offering a pathway toward improved interpretation and future prediction of dust‑related mechanisms in astrophysics.
BIO
Lile Wang obtained his B.S. in physics from Tsinghua University in 2012, and PhD in astrophysics from Princeton University in 2018. He then had postdoctoral studies in the Center for Computational Astrophysics of the Flatiron Institute before joining the faculty of the Kavli Institute for Astronomy and Astrophysics at Peking University in the year 2021. He is now mainly working on GPU-based high-performance algorithms for astrophysical simulations, and computational astrochemistry.
Host: Sharon Wang
