科学研究
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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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2023.04.28
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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2023.04.27
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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2023.04.26
21cm Cosmology in the Post-Reionization Universe
I will discuss some recent progress in 21cm line intensity mapping within the SKA cosmology science working group. In particular, we report the first direct detection of the cosmological power spectrum using 21cm line (2301.11943), derived from interferometric observations with the L-band receivers of the MeerKAT radio telescope. I review the challenges in analysing the MeerKAT data and present...
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2023.04.25
Unveiling BCGs and their host clusters using the ICL and Satellite Galaxy Populations
At the heart of every galaxy cluster is the brightest central galaxy (BCG). The central location of the BCG along with its unique formation history yield the underlying galaxy-dark matter halo connection. This statistical correlation allows us to enhance our understanding of the assembly and evolution of BCGs over cosmic time. However, we gain further insight into the formation and evolution of...
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