arXiv subjects

Mingqi Sun

Publications and source records attributed to Mingqi Sun.

4 recordsLinked to original sources

arXiv2026

Mock Catalogs of Strongly Lensed Gravitational Waves via a Halo Model Approach with Space-borne Detectors

Future space-borne gravitational-wave (GW) detectors, such as LISA and DECIGO, are expected to detect a large number of GW events, a fraction of which may be strongly lensed by intervening galaxies or galaxy clusters. In this work, we develop a comprehensive framework to simulate strongly lensed GWs in the context of space-borne detectors. Based on realistic astrophysical models for both the source population and the lens distribution, we construct mock catalogs of lensed GW events, referred to as \textbf{GW-LMC-Space}. Our results show that, for a four-year LISA observation, the expected number of lensed events ranges from $0$ to $131$, depending on the adopted formation model of massive black hole binaries (MBHBs). The corresponding lensing probability for MBHBs can reach up to $\sim 0.3\%$. For DECIGO, we find that the number of lensed events in a one-year observation is expected to lie in the range of $0$--$44$, with a lensing probability of $\sim 0.15\%$ for stellar-mass binary black holes (BBHs), binary neutron stars (BNSs), and neutron star--black hole binaries (NSBHs). We further show that the overlap of lensed signals is a common feature in space-borne detectors, which can significantly affect both the signal-to-noise ratio (SNR) estimation and event identification. These results highlight the importance of accounting for signal overlap in the analysis of strongly lensed GW events in future space-borne GW observations.

astro-ph.CO↗

arXiv2026

Mock Catalogs of Strongly Lensed Gravitational Waves via A Halo Model Approach with Ground-based Detectors

As plans for the construction of third-generation gravitational wave (GW) detectors advance, research into strongly lensed GWs has become increasingly critical. It is anticipated that hundreds of multi-image lensed GWs will be detected annually. We present a comprehensive suite of lensed GW mock catalog derived from a composite lens mass model incorporating dark matter halos, galaxies, and subhalos. We analyze three source populations with four detector network configurations considering the earth rotation. Our simulations encompass not only conventional doublets and quadruplets but also subhalo-lensed events, highly magnified systems, and complete three or five image systems with a detectable central image, a feature distinct from optical lensing. For the joint ET+CE network, we forecast an annual detection rate of approximately 400 doublets and 36 quadruplets. Notably, this population includes roughly 107 events lensed by subhalos and 20 complete systems with detectable central images. Furthermore, we analyze high-magnification events ($\mu > 3$), predicting approximately 360 such cases. Under a more relaxed selection criterion that requires only at least one lensed signal to exceed the detection threshold, we estimate a total of approximately 617 lensed events. We also investigate the impact of variations in lens mass models and stellar evolution models on event rates, as well as the distributions of SNR pairs and time delays. These results establish a more physically grounded statistical prior for the future identification and authentication of lensed GW signals. The Gravitational Waves-Lensing Mock Catalog (GW-LMC) have been made publicly available.

astro-ph.CO↗

arXiv2025

Probing Primordial black holes with the distortion of Stochastic Gravitational Wave Background

The stochastic gravitational-wave background (SGWB), arising from the incoherent superposition of numerous compact binary coalescences, serves as a powerful probe of both astrophysical populations and fundamental physics. In this work, we investigate the influence of gravitational lensing on the SGWB, focusing on primordial black holes (PBHs) as potential lenses. Assuming PBHs as dark matter candidates with a broad cosmic distribution, we show that their lensing optical depth can be significantly enhanced, producing pronounced effects with relative deviations at the 10^-1 level. By systematically varying the PBH mass (M_PBH) and abundance (f_PBH), we demonstrate that the mass predominantly determines the frequency-dependent diffraction features of the spectrum, while the abundance primarily amplifies the overall lensing-induced deviation. Although the SGWB from binary black holes has not yet been observed, our analytical results provide theoretical insight into the possible imprint of lensing on its spectrum and suggest that future detections could offer a novel avenue to constrain dark matter scenarios.

astro-ph.CO↗

arXiv2025

Probing stellar-mass primordial black holes with type Ia supernova microlensing

Gravitationally lensed quasars have served as a powerful tool for studying the composition of dark matter (DM) in lensing galaxies. In this work, we propose a novel method to investigate stellar-mass primordial black holes (PBHs) by using the microlensing effect of strongly lensed Type Ia supernovae (SNe Ia). Using the parameters of the lensed quasar system PG 1115+80, such as convergence, shear, and stellar/dark matter fractions, we generate microlensing magnification maps. A uniform brightness disk model is applied to these maps to evaluate the microlensing amplitude at different stages of the supernova explosion. We extend this analysis by employing the strong lensing parameters derived from the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) to create extensive image datasets of lensed SNe Ia. Utilizing these datasets and the Kolmogorov-Smirnov (KS) test, we compare two models: (1) the fiducial model, where galaxies are composed of stars and smooth DM, and (2) the alternative model, where galaxies consist of stars and compact DM, specifically PBHs. Our preliminary analysis predicts that at least 60 image datasets are required to distinguish these two scenarios at a 95 percent confidence level. Additionally, by incorporating the Strong Lensing Halo model-based mock catalogs (SL-Hammocks), which provide more realistic and precise image data, we refine our prediction to assess the data requirements for distinguishing cases where PBHs constitute fractions x of the total dark matter mass. Our findings indicate that 50, 55, and 65 image datasets, corresponding to compact dark matter fractions of 100 percent, 50 percent, and 25 percent (denoted by x), are necessary to distinguish between the specific models.

astro-ph.CO↗