arXiv subjects

Aoxiang Jiang

Publications and source records attributed to Aoxiang Jiang.

5 recordsLinked to original sources

arXiv2024

Minkowski Functionals of Large-Scale Structure as a Probe of Modified Gravity

In this study, we explore the potential of utilizing the four Minkowski functionals, which can fully describe the morphological properties of the large-scale structures, as a robust tool for investigating the modified gravity, particularly on non-linear and quasi-linear scales. With the assistance of the N-body simulation, we employ the Minkowski functionals to probe the Hu-Sawicki f(R) gravity model. The focus is on understanding the morphorlogical properties extracted by the Minkowski functionals and their sensitivity to modified gravity. Our analysis involves a comprehensive examination of the cosmic variance arising from finite simulation volumes. By systematically varying smoothing scales and redshifts, we quantify the information encoded in the Minkowski functionals measured from the dark-matter density field. The goal is to assess the capacity of the Minkowksi functionals to constrain the model and explore potential improvements through their combination. Additionally, we investigate the impact of using biased tracers such as dark matter halos and the halo occupation distribution galaxies on the modified gravity signatures within the Minkowksi functionals of the LSS. Furthermore, we evaluate the influence of the redshift space distortion on the observed results. In summary, our study suggests that the Minkowski functionals of the large-scale structures hold promise as a stringent tool for constraining modified gravity and offer valuable insights into the morphological features of the cosmic web.

astro-ph.CO↗

arXiv2023

Probing massive neutrinos with the Minkowski functionals of the galaxy distribution

The characteristic signatures of massive neutrinos on large-scale structure (LSS), if fully captured, can be used to put a stringent constraint on their mass sum, $M_ν$. Previous work utilizing N-body simulations has shown the Minkowski functionals (MFs) of LSS can reveal the imprints of massive neutrinos on LSS, provide important complementary information to two-point statistics and significantly improve constraints on $M_ν$. In this work, we take a step forward and apply the statistics to the biased tracers of LSS, i.e. the galaxies, and in redshift space. We perform a Fisher matrix analysis and quantify the constraining power of the MFs by using the Molino mock galaxy catalogs, which are constructed based on the halo occupation distribution (HOD) framework with parameters for the SDSS $M_r < -21.5$ and -22 galaxy samples. We find the MFs give tighter constraints on all of the cosmological parameters that we consider than the power spectrum. The constraints on $Ω_{\mathrm{m}}, Ω_{\mathrm{b}}, h, n_s, σ_8$, and $M_ν$ from the MFs are better by a factor of 1.9, 2.9, 3.7, 4.2, 2.5, and 5.7, respectively, after marginalizing over the HOD parameters. Specifically, for $M_ν$, we obtain a 1$σ$ constraint of 0.059 eV with the MFs alone for a volume of only $\left(1 h^{-1} \mathrm{Gpc}\right)^3$.

astro-ph.CO↗

arXiv2023

Dynamical hotness, star formation quenching and growth of supermassive black holes

A stellar system is dynamically hot when its kinetic energy is dominated by random motion represented by the velocity dispersion $σ_{\rm hot} (M_*)$. We use MaNGA data to obtain inner and outer dispersion of a galaxy, $σ_{\rm in}$ and $σ_{\rm out}$, to characterize its dynamical status and study its connection with star formation quenching and the growth of supermassive black hole (SMBH). We divide galaxies into fully quenched (FQGs), partially quenched (PQGs) and fully star-forming (FSGs) populations, and identify quenched central cores (QCCs) in PQGs. The galaxy distribution in $σ_{\rm in}/σ_{\rm hot}$-$σ_{\rm out}/σ_{\rm hot}$ diagram is L-shaped, consisting of a horizontal sequence ($σ_{\rm out}/σ_{\rm hot}\sim0$) and a vertical sequence ($σ_{\rm in}/σ_{\rm hot}\sim1$). FQGs and QCCs are located at the top of vertical sequence, $σ_{\rm out}/σ_{\rm hot}\sim1$, therefore they are dynamically hot over their entire bodies. PQGs reside along vertical sequence, so they have hot center but cold outskirt. FSGs are diverse and can be found in both sequences. Galaxy structural properties, star formation and AGN activities make a transition along horizontal sequence at $\log(σ_{\rm in}/σ_{\rm hot})\sim-0.3$, and along vertical sequence at $\log(σ_{\rm out}/σ_{\rm hot})\sim-0.3$. The fractions of optical AGNs and barred galaxies increase rapidly in the first transition and decline rapidly in the second; radio galaxies are located at the top of vertical sequence. Our results demonstrate that star formation quenching and SMBH growth are effective only in dynamically hot systems. A simple model along this line can reproduce the observed SMBH scaling relations. We discuss how secular processes and strong interactions can make a system dynamically hot, and lead to the SMBH growth and star formation quenching.

astro-ph.GA↗

arXiv2022

Probing massive neutrinos with the Minkowski functionals of large-scale structure

Massive neutrinos suppress the growth of structure under their free-streaming scales. The effect is most prominent on small scales where the widely-used two-point statistics can no longer capture the full information. In this work, we study the signatures massive neutrinos leave on large-scale structure (LSS) as revealed by its morphological properties, which are fully described by $4$ Minkowski functionals (MFs), and quantify the constraints on the summed neutrino mass $M_ν$ from the MFs, by using publicly available N-body simulations. We find the MFs provide important complementary information, and give tighter constraints on $M_ν$ than the power spectrum. Specifically, depending on whether massive neutrinos are included in the density field (the `m' field) or not (the `cb' field), we find the constraint on $M_ν$ from the MFs with a smoothing scale of $R_G=5 h^{-1}$Mpc is $48$ or $4$ times better than that from the power spectrum. When the MFs are combined with the power spectrum, they can improve the constraint on $M_ν$ from the latter by a factor of 63 for the `m' field and 5 for the `cb' field. Notably, when the `m' field is used, the constraint on $M_ν$ from the MFs can reach $0.0177$eV with a volume of $1(h^{-1}\rm Gpc)^3$, while the combination of the MFs and power spectrum can tighten this constraint to be $0.0133$eV, a $4.5σ$ significance on detecting the minimum sum of the neutrino masses. For the `m' field, we also find the $σ_8$ and $M_ν$ degeneracy is broken with the MFs, leading to stronger constraints on all 6 cosmological parameters considered in this work than the power spectrum.

astro-ph.CO↗

arXiv2022

The effects of peculiar velocities on the morphological properties of large-scale structure

It is known that the large-scale structure (LSS) mapped by a galaxy redshift survey is subject to distortions by galaxies' peculiar velocities. Besides the signatures generated in common N-point statistics, such as the anisotropy in the galaxy 2-point correlation function, the peculiar velocities also induce distinct features in LSS's morphological properties, which are fully described by four Minkowski functionals (MFs), i.e., the volume, surface area, integrated mean curvature and Euler characteristic (or genus). In this work, by using large suite of N-body simulations, we present and analyze these important features in the MFs of LSS on both (quasi-)linear and non-linear scales, with a focus on the latter. We also find the MFs can give competitive constraints on cosmological parameters compared to the power spectrum, probablly due to the non-linear information contained. For galaxy number density similar to the DESI BGS galaxies, the constraint on $σ_8$ from the MFs with one smoothing scale can be better by $\sim 50\%$ than from the power spectrum. These findings are important for the cosmological applications of MFs of LSS, and probablly open up a new avenue for studying the peculiar velocity field itself.

astro-ph.CO↗