Research
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2024.04.01
Baryon Recycle in Disc Galaxy
We utilize the public Gizmo code to simulate twelve galaxies from the NIHAO suite simulated with the ESF-Gasoline2 code, then compare the corresponding galaxies in the two simulations. We find that while both codes with the same initial conditions and large-scale environments can successfully produce similar disc galaxies, significant differences are still seen in many properties of the galaxie...
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2024.03.25
Primordial non-Gaussianity (PNG) and Its Detection by Cosmolgical Surveys
The simplest single-field inflation models predict a nearly Gaussian distribution of primordial density perturbations. However, the non-Gaussianity of the primordial density field serves as a powerful probe into the physics of the early universe, especially when considering more complex inflation models. The Cosmic Microwave Background (CMB) bispectrum has provided the tightest constraint on th...
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2024.03.15
Can we test cosmic homogeneity and isotropy?
The Cosmological Principle (CP) was a major achievement of modern cosmology to turn qualitative statements into quantitative ones. It makes the strong assumption that space is globally homogeneous and isotropic. By doing so, it reduces Einstein’s Field Equations to provide highly symmetric cosmological models. The latter then enable us to interpret a very sparse amount of data and put them int...
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2024.03.08
A decelerating bar in the Galaxy
The bar of the Galaxy is believed to slow down. We use an axisymmetric background potential plus a central bar model to perform the test particle simulations in order to investigate the possible origin of the phase space spirals and the thin-disc-like low-metallicity stars (VMPs). The Gaia data reveal a two-armed phase spiral pattern in the local plane inside the solar radius. On the contrary,...
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2024.03.04
Towards a Unified Model of Dwarf Galaxy Star Formation and Halo Connection with UniverseMachine
Dwarf galaxies provide rich constraints on galaxy formation, reionization, and the nature of dark matter. However, flexible models of their star formation histories in a cosmological context are lacking. We introduce a novel framework for connecting dwarf galaxy dark matter assemblies and star formation histories based on the empirical model UniverseMachine (UM). Our framework is flexible, such...
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