Research
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2023.04.27
Formation of hot Jupiters in star clusters
It has been suggested that the occurrence rate of hot Jupiters (HJs) in some open clusters might reach several per cent, significantly higher than that of the field. Several models have been proposed to solve this problem but none has been satisfactory. In a binary-rich cluster, the von Zeipel-Lidov-Kozai (ZKL) mechanism may cause the observed high occurrence rate. For planets formed around a s...
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2023.04.28
Alternative theories of gravity and their tests using astronomy observations
General relativity is currently the standard theory to describe gravity. It has passed all the tests in our Solar System and has been positively supported by astronomy observations including electromagnetic waves from neutron stars and gravitational waves from coalescing compact binary systems. But fundamentally it is incompatible with quantum theory, and there are also the large-scale observat...
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2023.05.10
cosmological tests on fundamental physics
The precision measurements from current observational cosmology have established the Lambda-Cold-Dark-Matter (LCDM) model as the standard cosmological model. However, the LCDM model as a pure phenomenological model with six base parameters still calls for a theoretical understanding of underlying mechanisms for the early and late accelerations as well as the nature of dark matter. In this talk,...
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2023.05.10
A dynamical model and structure decomposition of barred galaxies
Galaxy structures are fossil records of their assembly history. Modern IFU spectrographs offer the ability to map the spatial distribution of the motions, ages, and chemical abundances of stars in galaxies, which provide unprecedented detailed view of galaxies structures. But the information are still blended along the line-of-sight. Decomposition of galactic structures in a physical way is cha...
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2023.05.11
Ultra-Diffuse Galaxies lacking dark matter: from properties to formation
The formation of ultra-diffuse galaxies (UDGs) is not well-understood. UDGs have large sizes (several kpc) for their dwarf-galaxy-like stellar mass and have a wide range in dark matter content and other observed properties. In particular, NGC1052-DF2 and NGC1052-DF4 are two puzzling UDGs: they have low-velocity dispersions indicating little to no dark matter content, as well as overly luminous ...
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