arXiv subjects

Shuangxi Yi

Publications and source records attributed to Shuangxi Yi.

6 recordsLinked to original sources

arXiv2026

Galactic constraints on spinning primordial black hole dark matter from interstellar dust heating

Primordial black holes (PBHs) are compelling dark matter candidates. PBHs with masses between $10^{15}$ and $10^{18}\,\mathrm{g}$ can heat interstellar dust via Hawking radiation. Previous studies of this dust heating mechanism mostly neglected PBH spin and adopted a single dark matter halo profile. In this work, we incorporate PBH spin, which substantially enhances the emitted radiation flux, and systematically investigate the dependence of constraints on the dark matter density distribution by considering five different halo models. We compute the complete photon spectra, including both primary and secondary emissions. Our results show that, for a fixed profile and mass function, larger spin parameters yield stronger constraints on the PBH fraction $f_{\mathrm{PBH}}$. Among the halo models, the Isothermal profile gives the most stringent limits, followed by Einasto, then NFW and Moore, while the Burkert profile yields the weakest constraints. For silicate grains, which cool less efficiently than graphite, the upper limits reach $\mathcal{O}(10^{-4})$ for high spin cases. We consider both monochromatic and lognormal mass functions, and find consistent trends between them. For the lognormal case, larger values of the width $σ$ lead to a broader mass range being excluded, in particular ruling out massive PBHs as the sole dark matter component. Our bounds are generally weaker than other existing limits, but they provide a complementary and independent constraint.

astro-ph.CO↗

arXiv2026

Redshift evolution of the Hubble constant: Constraints and new insights from an interacting dark energy model

We develop a modified interacting dark energy (IDE) model to study the redshift evolution of the Hubble constant ($H_0$), in light of the Hubble tension. In this framework, the energy exchange between dark energy and dark matter induces a redshift dependence of $H_0$. We evaluate the model against a comprehensive suite of observations, including baryon acoustic oscillations (BAO) from DESI DR2 and SDSS, cosmic chronometers, type Ia supernovae from the Pantheon sample, and Planck CMB distance priors. Analysis of late-Universe data yields $α= 0.0107^{+0.0032}_{-0.011}$, with the best-fit value on the order of $10^{-2}$, revealing a decreasing trend of $H_0$ with redshift. This supports a power-law evolution beyond $Λ$CDM. Incorporating CMB data further tightens the constraint to the order of $10^{-5}$, which we attribute to the suppression of dark-sector interactions at high redshifts, a consequence of the strong baryon--photon coupling. These results indicate that the IDE framework provides a theoretically consistent and observationally viable mechanism for describing the redshift evolution of $H_0$, offering a promising avenue toward alleviating the Hubble tension.

astro-ph.CO↗

arXiv2026

Cosmological constraints on the big bang quantum cosmology model

The big bang quantum cosmology model introduces the trace $J$ of the Schouten tensor as a form of dynamic dark energy. Together with cold dark matter, these components form the so-called $J$CDM cosmology model, proposed by M.H.P.M. van Putten (J. High Energy Astrophys., 45, 2025, 194), which offers a potential resolution to the Hubble tension. We derive the constraints on the $J$CDM cosmology model, utilizing early- and late-time cosmological data including cosmic microwave background (CMB), baryon acoustic oscillations (BAO) released by the Dark Energy Spectroscopic Instrument (DESI), cosmic chronometers (CC), and type Ia supernovae (SNIa). For a flat universe, the $J$CDM model yields $ H_0 = 66.95 \pm 0.51 \, \rm{km~s^{-1}~Mpc^{-1}} $ and $ Ω_m = 0.3419 \pm 0.0065 $, results that are consistent with early-universe observations but exhibit a higher $ Ω_m $ compared to the $Λ$CDM model. In the case of a non-flat universe, $J$CDM favors a slightly curved geometry with $ Ω_k = 0.0154 \pm 0.0027 $, leading to $ H_0 = 69.13 \pm 0.56 \, \rm {km~s^{-1}~Mpc^{-1}} $ and $ Ω_m = 0.3477 \pm 0.0074 $. The increase in $ H_0 $ in the non-flat scenario suggests a geometric degeneracy between spatial curvature and $ H_0 $. We also investigate the internal inconsistencies present in DESI data and evaluate their impacts on cosmological parameter constraints. Our analysis shows that while the $J$CDM model, which is constructed from first principles without free parameters beyond those of $Λ$CDM, agrees excellently with late-time cosmology, it struggles to simultaneously match early-universe observations in a fully self-consistent manner.

astro-ph.CO↗

arXiv2024

Muon neutrinos and the cosmological abundance of primordial black holes

In the mixed dark matter scenarios consisting of primordial black holes (PBHs) and particle dark matter (DM), PBHs can accrete surrounding DM particles to form ultracompact minihalos (UCMHs or clothed PBHs) even at an early epoch of the Universe. The distribution of DM particles in a UCMH follows a steeper density profile compared with a classical DM halo. It is expected that the DM annihilation rate is very large in UCMHs, resulting in a contribution to, e.g., the extragalactic neutrino flux. In this work, we investigate the extragalactic neutrino flux from clothed PBHs due to DM annihilation, and then the muon flux for neutrino detection. Compared with the atmospheric neutrino flux, we derive the upper limits on the cosmological abundance of PBHs for 10 years of exposure time of, e.g., the IceCube experiment. Compared with other constraints, although the upper limits obtained by us are not the strongest, it is a different way to study the cosmological abundance of PBHs.

astro-ph.CO↗

arXiv2022

Hypercritical Accretion for Black Hole High Spin in Cygnus X-1

Recent observations of AdLIGO and Virgo have shown that the spin measurements in binary black hole (BH) systems are typically small, which is consistent with the predictions by the classical isolated binary evolution channel. In this standard formation channel, the progenitor of the first-born BH is assumed to have efficient angular momentum transport. The BH spins in high-mass X-ray binaries (HMXBs), however, have been found consistently to be extremely high. In order to explain the high BH spins, the inefficient angular momentum transport inside the BH progenitor is required. This requirement, however, is incompatible with the current understanding of conventional efficient angular momentum transport mechanism. We find that this tension can be highly alleviated as long as the hypercritical accretion is allowed. We show that, for a case study of Cygnus X-1, the hypercritical accretion cannot only be a good solution for the inconsistent assumption upon the angular momentum transport within massive stars, but match its other properties reported recently.

astro-ph.HE↗

arXiv2018

Thermodynamics of general flat space and boson star quasi-local systems

We study thermodynamics of flat space/boson star systems enclosed in a scalar reflecting box with St$\ddot{u}$ckelberg mechanism. We also disclose effects of model parameters on transitions and the properties appear to be qualitatively the same as those in holographic St$\ddot{u}$ckelberg transitions. Moreover, we obtain a relation $\barζ\thickapprox 2 \tildeζ$ and the second order characteristic exponent, which also hold in holographic superconductor theories. The similarity between quasi-local thermodynamic transitions and holographic transitions provides additional evidences that holographic theories may also exist in the quasi-local space.

hep-th↗