高能暂现源 · 每日文献综述

HIGH-ENERGY TRANSIENTS · DAILY LITERATURE REVIEW
2026 年 7 月 12 日 星期日 · 数据截至 arXiv / ADS 最新收录日
I.

当日总览

今日共收录5篇文献,包含1篇核心文献与4篇相关文献。主题分布聚焦于高能暂现天体(3篇,涵盖超新星与X射线双星)、引力波电磁对应体/千新星(1篇)及多信使天体粒子物理学科史(1篇)。

II.

核心文献

1 篇
01
优先级 95 · kilonova · 引力波电磁对应体 · 中子星并合

Late-time emission-line profiles from kilonova models

千新星模型晚期的发射线轮廓

S. A. Sim (Astrophysics Research Centre, Queen's University Belfast), O. Just (GSI Helmholtzzentrum für Schwerionenforschung, RIKEN), Z. Xiong (GSI Helmholtzzentrum für Schwerionenforschung), et al.

原文摘要Abstract

Numerical simulations suggest that neutron star mergers eject material with complex, non-spherical density and composition distributions. Here we use two-dimensional configurations of merger ejecta obtained from long-term hydrodynamic simulations to quantify the influence of such ejecta structure on the shapes of spectral lines in the optically thin limit. We consider three example elements of interest for kilonova modelling (selenium, tellurium and tungsten) and illustrate profile shapes for a sample of models and observer orientations. Many of our calculations yield complex profile shapes, including cases with multiple peaks and/or extended wings on scales large enough to be relevant to interpreting observations. For selenium and tellurium, our late-phase profile shapes are most sensitive to the structure of the low-velocity ejecta (~0.1c) launched after the merger from the relic black-hole torus system, while for heavier elements the contribution from the more rapidly expanding and more neutron-rich dynamical ejecta launched right after the merger is more significant and leads to broader line shapes. We also find that the dynamical influence of heating due to the decay of r-process elements can lead to considerably broader peaks than suggested by models that neglect this effect. Although idealised, our calculations demonstrate that line shapes are sensitive to the ejecta structure and could therefore constrain the polar observation angle or underlying properties of the merger that determine the spatial distributions of elements in the ejecta components, such as the binary mass ratio or even the equation of state of high-density matter.

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AI 综述 AI-generated · 以原文为准
亮点

首次基于长期动力学模拟的二维抛射物结构计算多种元素的线轮廓,发现线轮廓可呈现多峰、扩展翼等复杂形态,r-过程加热显著展宽线心,并指出这些特征可约束并合参数及观测倾角。

脉络与展望

千新星早期光谱由于高光深呈现球对称特征 Sneppen+ 2023,但晚期光学薄时线轮廓可反映抛射物几何 Jerkstrand 2017。以往多数晚期发射线研究采用一维或高斯近似 Hotokezaka+ 2023,而本文基于二维并合模拟 Just+ 2023 首次系统探究了不同元素在不同方向的轮廓变化。未来需要在三维模型中考虑温度/电离梯度、谱线混叠和残余光深 Pognan+ 2023,有望通过线轮廓观测约束径向元素分层及并合参数如质量比和状态方程 Sneppen+ 2026

边缘相关 26 篇 · 低相关性展开 +
优先级 30 · 高能暂现天体 · 超新星

Nucleosynthesis of Pop III and Fe-enriched Pop II Pair-Instability Supernovae

Wenyu Xin, Ken'ichi Nomoto, Chun-Ming Yip, et al.

原文摘要Abstract

Recently discovered very metal-poor (VMP) star LAMOST J1010+2358 shows a peculiar abundance pattern that is remarkably well fit by a Pop III pair-instability supernova (PISN) of $\simeq 260$ M$_\odot$. Motivated by this, we investigate the nucleosynthetic characteristics of Pop III and Pop II PISNe to provide theoretical constraints for future observations. This paper is divided into two parts. First, we explore the evolution and nucleosynthesis of Pop III PISNe with initial masses of 130 - 300 M$_\odot$. Our main aim is to investigate how the uncertainty in $^{12}$C$(α,γ)^{16}$O and $^{16}$O+$^{16}$O reaction rates affect their explosion properties and nucleosynthesis. We find that the yields of odd-$Z$ elements are particularly sensitive to the $^{12}$C$(α,γ)^{16}$O rate, while the production of Fe-peak elements shows significant sensitivity to both rates. Second, we investigate the nucleosynthetic features of Pop II PISNe formed in gas enriched exclusively by Pop III PISN ejecta. By employing a time-dependent convection model during the explosion, we demonstrate that metal enrichment increases opacity and triggers vigorous convective mixing. This hydrodynamic effect significantly enhances the explosion energy and $^{56}\text{Ni}$ production. Consequently, Pop II PISNe exhibit distinct chemical signatures, including a weaker odd-even effect and enhanced Zn-Ge production, providing unique diagnostics for identifying PISN remnants in the early Universe.

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Pop III和富Fe Pop II对不稳定超新星的核合成 · 研究了Pop III和Pop II对不稳定超新星的核合成,发现核反应速率影响元素产额,金属富集通过增强对流混合提高爆炸能量和56Ni生成,并产生独特化学特征。

优先级 25 · 暗物质

Do primordial quark pellets solve the dark matter puzzle?

Domenec Espriu

原文摘要Abstract

We show that primordial quark pellets (PQP), ultra dense quark matter mini-stars formed at around 1 TeV, naturally arise in a radiation dominated universe if rare baryon overdensities are produced by collapsing Peccei-Quinn domain walls or similar superhorizon structures. Solving the Tolman-Oppenheimer-Volkoff equation with a hot quark equation of state, we find stable solutions with a maximum mass of $10^{-2}$ solar masses and radii of approximately 100 meters, although the formation mechanism favours much smaller objects. Once formed, PQPs cool and evolve intro mini neutron stars or stable strange matter nuggets, depending on the QCD ground state. Formation probabilities of $10^{-9}$ to $10^{-4}$ per horizon volume could suffice to reproduce the present dark matter density without altering Big Bang Nucleosynthesis or requiring entropy dilution. PQPs completely evade microlensing constraints if their mass is below $10^{-7}$ solar masses, a range that could easily accommodate most of the dark matter. PQPs thus potentially constitute a conservative, Standard-Model based, and observationally testable solution to the dark matter puzzle.

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原始夸克粒团能否解决暗物质之谜? · 本文提出原始夸克粒团(PQP)作为暗物质候选体,论证其在早期宇宙中自然形成,并分析其稳定性、演化及对现有观测约束的规避。

优先级 20 · 恒星核合成 · 核反应率

Closed-form representations of extended astrophysical thermonuclear functions

Subrat Parida

原文摘要Abstract

Reaction rate determination is an essential problem in the theories of cosmological and stellar nucleosynthesis. I investigate the closed-form analytic evaluation of thermonuclear reaction rates, which are necessary for both cosmic and celestial nucleosynthesis. An alternate velocity distribution to the Maxwell-Boltzmann distribution can be considered in nuclear fusion processes occurring in the interior of stars when there is a diversion from hydrostatic equilibrium. The extension of non-resonant reaction rate integrals in standard, cut-off, depletion, and screening instances is examined in this study, utilising the MacDonald distribution. This study is primarily on the use of generalized special functions that represent the extended non-resonant thermonuclear functions in mathematical physics. Moreover, an attempt is made to analyse the reaction probability integrals corresponding to the several forms of the slowly varying cross-section factor S(E).

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扩展的天体物理热核函数的闭式表示 · 本文利用MacDonald分布和广义特殊函数,给出了扩展非共振热核反应速率积分的闭式表示,并分析了反应概率积分。

优先级 20 · 宇宙线/暗物质

The KM3NeT 220 PeV event: a neutrino messenger from the grand unification scale?

Vernon Barger

原文摘要Abstract

The 220~PeV neutrino KM3-230213A, in tension with IceCube and Auger unless narrow, admits a two-body reading: relic decay $X \to ν\barν$ with $m_X \approx 4.4\times10^{8}$~GeV. Consistency with neutrino and $γ$-ray bounds sets $τ/f \approx 10^{29}$--$10^{30}$~s, lifetime over relic fraction. For a flavored $^1S_0$ onium, the operator scale lands in the Majorana-mass range of unified models: one Higgs insertion gives a singlet mediator, $M/|C_7|^{1/3} \approx 10^{14}$--$10^{16}$~GeV across the allowed relic fraction; two give the seesaw window; Dirac or Majorana neutrinos select the branch. We give the construction and its decisive tests.

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KM3NeT 220 PeV事件:来自大统一能标的中微子信使? · 本文提出KM3NeT的220 PeV中微子事件由质量约4.4×10^8 GeV的宇宙遗迹衰变产生,并论证其与大统一能标一致,给出了模型构建和决定性检验。

优先级 20 · 宇宙线 · 高能天体物理

Detector-level simulation closure of radio air-shower reconstruction with fixed equal-prior geomagnetic templates

Xin Xu, Pengfei Zhang, Fufu Yang

原文摘要Abstract

Autonomous radio arrays reconstruct air showers from trigger-selected ADC traces rather than from ideal electric-field footprints. We present a detector-level simulation-closure test that connects RF-chain-triggered ZHAireS event packages to direction, energy and quality labels. Geometry is reconstructed from voltage amplitudes and station timing. The ADC traces are then inverted through the RF chain, restricted to 50--200 MHz and reduced to the geomagnetic peak amplitude $|E_{x_π}|$ in a radio-core-recentered shower plane. Energy is obtained by fitting a fixed equal-prior mean of locked iron and proton template families. The estimator uses neither the simulated primary label nor an empirical amplitude or zenith scale. Of 972 event packages, 711 pass a common reconstructed-quality gate in the raw-noisy weighted, raw-hard-denoised equal-weight and clean-reference branches. Their mean fractional energy residuals are $+1.20\%$, $+0.55\%$ and $-0.10\%$, with event-to-event scatters of $14.51\%$, $14.40\%$ and $14.25\%$, respectively. The median truth-level opening-angle residual is $0.050^\circ$ in this selected simulated sample. These aggregate values conceal a zenith-dependent energy residual, from about $-8\%$ at $60^\circ$--$70^\circ$ to $+11\%$ at $80^\circ$--$85^\circ$, with substantially larger biases in sparsely populated edge bins. The results establish an internally consistent reconstruction baseline for selected simulated event packages, not a deployed-array resolution or exposure.

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使用固定等先验地磁模板的射电空气簇射重建的探测器级模拟闭合 · 本文通过固定等先验地磁模板和射频链反演,在探测器级模拟中实现了射电空气簇射重建的闭合测试,验证了方向与能量重建的精度。

优先级 20 · 暗物质 · 宇宙学 · 量子修正

Quantum corrections as a Bound for Detecting Self-Interacting Ultralight Dark Matter

Jae-Weon Lee, Chueng-Ryong Ji

原文摘要Abstract

We investigate the implications of the interactions between ultralight dark matter (ULDM) and the Standard model particles for the effective self-interaction coupling constants of ULDM. Our analysis shows that one-loop quantum corrections can result in a substantial increase in the effective coupling constant, which is tightly constrained by cosmological observations. Our findings highlight the importance of considering quantum corrections in the detection of ULDM.

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量子修正作为探测自相互作用超轻暗物质的约束边界 · 研究超轻暗物质与标准模型粒子相互作用对有效自相互作用的影响,发现单圈量子修正显著增加耦合常数,受宇宙学观测约束。

优先级 20 · 暗物质 · 原初黑洞

Constraining primordial black holes and primordial curvature power spectrum with extragalactic muon neutrino

Yupeng Yang

原文摘要Abstract

We investigate a mixed dark matter scenario comprising weakly interacting massive particles (WIMPs) and primordial black holes (PBHs). After PBH formation, WIMPs can accrete onto them, forming ultracompact minihalos (UCMHs). The resulting WIMP number density within UCMHs is significantly enhanced compared to classical dark matter halo models, leading to a higher WIMP annihilation rate. Previous studies have focused mainly on the associated gamma-ray flux, we investigate the extragalactic neutrino flux from such annihilation. Considering the annihilation channels $μ^{+}μ^{-}$, $τ^{+}τ^{-}$, and $ν_μ\barν_μ$, we analyze two classes of neutrino events: upward and contained events. By requiring the neutrino flux from WIMP annihilation around PBHs does not exceed the atmospheric neutrino background, we derive upper limits on the fraction of dark matter in PBHs ($f_{\rm PBH}$) for a one-year exposure of the IceCube experiment. These limits depend on the annihilation channel, the masses of the WIMP and PBH, and the neutrino event type. The strongest constraints come from the $ν_μ\barν_μ$ channel, yielding $f_{\rm PBH} \sim 10^{-4}$ ($4\times 10^{-5}$) for contained (upward) events with $m_χ=10^{3}$ GeV and $M_{\rm PBH}=10^{3} M_{\odot}$. Based on these bounds on PBHs, we further derive upper limits on the primordial curvature power spectrum $\mathcal{P}_{\mathcal{R}}$. From our strongest constraint, we obtain $\mathcal{P}_{\mathcal{R}} \sim 10^{-1.65}$ at the scale $k\sim 3\times 10^{12}~\mathrm{Mpc^{-1}}$.

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用河外缪子中微子约束原初黑洞和原初曲率功率谱 · 研究WIMP吸积到原初黑洞形成超紧凑微晕,通过湮灭产生的河外中微子通量,结合IceCube数据导出PBH占暗物质比例上限和原初曲率功率谱上限。

优先级 15 · 引力波

On correlated noise in the LIGO-Virgo network: a test of the stochastic gravitational-wave background hypothesis

S. C. Ulhoa, B. C. C. Carneiro, F. L. Carneiro, et al.

原文摘要Abstract

We revisit the inter-detector cross-correlation criterion used in gravitational-wave validation by extending the analysis of Creswell et al.~\cite{Creswell2017} to nine LIGO--Virgo candidate events from the O2 and O3 observing runs. For each event, we analyze all three detector pairs (H1$\times$L1, H1$\times$V1, L1$\times$V1) and compare the normalized cross-correlation function $C(τ)$ in the event window with an empirical ensemble of $N=200$ surrounding off-source windows, using a band-pass-only pipeline. In 26 of 27 pair-measurements, the event peak is statistically indistinguishable from the corresponding noise ensemble, including all pairs involving the independent Virgo detector. The only exception is GW190412 in the H1$\times$L1 pair. We conclude that the cross-correlation statistic does not provide a robust standalone separation between event and noise. We interpret the persistence of comparable correlation structure in the LIGO--Virgo pairs as evidence that the strain data may contain a continuous correlated physical component, for which a stochastic gravitational-wave background is a plausible candidate.

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关于LIGO-Virgo网络中的相关噪声:对随机引力波背景假设的测试 · 本文通过分析LIGO-Virgo探测器对的互相关函数,发现除GW190412外,26个候选事件对的互相关统计量与噪声不可区分,表明存在连续相关成分,随机引力波背景是一个合理候选解释。

优先级 15 · 黑洞理论 · 偏振

Polarization-dependent observational signatures of Weyl-coupled photons around a black hole

Mao-Yuan Wan, Chen Wu

原文摘要Abstract

A photon coupled non-minimally to the Weyl tensor propagates differently in its two linear polarization states: the vacuum around a black hole becomes a birefringent medium. On a Schwarzschild background the coupling $α$ splits the photon sphere and the critical impact parameter of the two polarizations, producing a double shadow and a polarization-dependent photon ring; the two shadow edges separate by $62\%$ of the shadow radius at $α/M^2=0.75$. We compute a unified set of wave-optical and geometric-optical observables for both polarizations across a range of $α$: greybody factors, absorption cross sections, differential cross sections and their glories, a backward birefringence signal, shadows, photon rings, and null trajectories. The two-polarization scattering matrices are extracted with a Riccati--Hankel matching scheme that keeps the phase-sensitive observables reliable, and the geometric-optics chain is cross-validated with three independent ray tracers. The cleanest diagnostic is the backward signal: it is protected by parity and vanishes identically at $α=0$.

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黑洞周围外尔耦合光子的偏振相关观测特征 · 论文研究了光子与Weyl张量非最小耦合在Schwarzschild黑洞背景下导致的偏振依赖传播差异,计算了从波光学到几何光学的多种观测信号(灰体因子、吸收截面、微分截面、后向信号、阴影和光子环),并指出后向双折射是零耦合下消失的干净诊断特征。

优先级 10 · 引力理论 · 后牛顿动力学

Post-Newtonian N-Body Dynamics in Extended Theories of Gravity

Antonio Tedesco

原文摘要Abstract

We derive the complete first post-Newtonian (1PN) Lagrangian and corresponding equations of motion for the relativistic $N$-body system in Scalar-Tensor-Fourth-Order Gravity (STFOG), including the Non-Commutative Spectral Geometry (NCSG) sector as a special case. In the regime $Φ\sim Ψ$ ($γ\sim 1$), the linearized fourth-order field equations are solved in the Standard Post-Newtonian gauge, and the variational Lagrangian is built directly from the point-particle action. The resulting dynamics is governed by three Yukawa functions $ζ$, $\mathcal{W}$ and $Ξ$, which encode the scalar, gravitomagnetic and three-body sectors and depend on the effective masses $(m_R,m_Y,m_φ)$ of the additional propagating modes. In this context, we show that the nonlinear metric component ${}^{(4)}\!g_{00}$ plays no role at 1PN level. The 1PN orbital motion of the above extended theories is thus obtained in closed form, and the Einstein--Infeld--Hoffmann equations are recovered in the corresponding general-relativistic limit. The formalism provides a common framework for the relativistic celestial mechanics of the Solar System, binary pulsars such as PSR J0737-3039, Galactic-center stellar orbits and triple systems.

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扩展引力理论中的后牛顿N体动力学 · 推导了标量-张量-四阶引力理论中完整的1PN N体拉格朗日量和运动方程,并得到闭合形式的轨道运动,在广义相对论极限下恢复爱因斯坦-因费尔德-霍夫曼方程。

优先级 10 · 暗物质 · 原初引力波

Conformal dark matter and MHz gravitational waves

Imtiaz Khan, Niamat Ullah, Salvatore Capozziello, et al.

原文摘要Abstract

A localized enhancement of the primordial curvature spectrum can leave two distinct relics: gravitationally produced conformal-fermion dark matter and a scalar-induced stochastic gravitational-wave background. We show that the dark-matter abundance fixes the scalar normalization through the cubic moment of the curvature spectrum, while the induced tensor signal probes its quadratic convolution. This closes the usual normalization freedom in scalar-induced gravitational-wave templates and ties the MHz signal directly to the dark-matter mass, peak scale, and spectral width. A concrete single-field realization demonstrates this mechanism: a Mukhanov--Sasaki evolution produces a broad MHz background that sits safely below the Gaussian primordial-black-hole threshold. In this construction, a null high-frequency search becomes a lower bound on the conformal-fermion mass, while a detection has to reproduce the relic abundance, peak frequency, amplitude, and width from one primordial feature. The result is a testable link between small-scale inflationary structure, superheavy dark matter, and laboratory MHz gravitational-wave searches

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共形暗物质与兆赫引力波 · 论文建立了原初曲率谱增强、共形费米子暗物质和MHz引力波之间的联系,通过暗物质丰度和引力波信号约束原初谱参数,在小尺度暴涨结构、超重暗物质和实验室MHz引力波搜索之间搭建了可检验的桥梁。

优先级 10 · 理论物理 · 黑洞量子力学

Quantum Horizon and Quantum Membrane Paradigm from Black Hole Quantum Mechanics

Chong-Sun Chu

原文摘要Abstract

We develop a microscopic quantum membrane paradigm from the matrix quantum mechanics of black holes [1]. It was proposed that a quantum black hole is described by a fuzzy sphere together with a half-filled Fermi sea of horizon partons. We show that the topology of the fuzzy sphere induces a Berry monopole, providing a microscopic origin for the monopole appearing in the tunneling description of the decay of quantum black hole. Because the partons couple to the fuzzy sphere as fundamental degrees of freedom, they are sensitive to this monopole and form Lowest-Landau-Level (LLL) states rather than ordinary propagating two-dimensional fermions. Their guiding-center dynamics generates Ohmic, Hall, and polarization currents on the horizon. To couple these currents to an external electromagnetic field, we introduce a two-block matrix configuration comprising black-hole, environmental, and bifundamental link sectors. Off-diagonal link modes become tachyonic near the fuzzy sphere and condense, dynamically locking the horizon gauge field to the boundary value of the external Maxwell field. The parton current thereby becomes a physical boundary source for the exterior field. Our construction replaces the fictitious membrane of the classical paradigm with a dynamical quantum membrane populated by microscopic LLL degrees of freedom. The resulting boundary condition generalizes the classical ingoing membrane condition and yields explicit quantum, frequency-dependent, and helicity-dependent corrections, offering a possible probe of the microscopic quantum structure of the horizon.

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黑洞量子力学中的量子视界与量子膜范式 · 本文基于黑洞矩阵量子力学发展了一种微观量子膜范式,其中模糊球上的部分子形成最低朗道能级态,并通过链接模式凝聚将视界规范场动态锁定到外部场的边界值,从而取代经典虚构膜并导出了量子、频率与螺旋性依赖的边界条件修正。

优先级 5 · 宇宙微波背景 · 宇宙学

GroundBIRD: First On-Sky Responsivity Calibration at the Teide Observatory

Alessandro Fasano, Yonggil Jo, Ricardo Tanausú Génova-Santos, et al.

原文摘要Abstract

GroundBIRD is a cosmic microwave background (CMB) experiment located at the Teide Observatory (altitude $\sim2400$ m, Spain) designed to measure large-angular-scale intensity and polarization anisotropies ($\ell \gtrsim 6$ to $\ell \sim 300$) to constrain the reionization optical depth, $τ$. The instrument employs a rapidly rotating telescope with a fixed elevation of $70$ deg and is equipped with 161 lenslet-coupled kinetic inductance detectors (KIDs): 138 at 145 GHz for CMB observations and 23 at 220 GHz for thermal dust characterization, all operated at $\sim280$ mK. This scan strategy provides daily coverage of $\sim$40% of the Northern Hemisphere sky. We present the first on-sky responsivity calibration model for GroundBIRD, derived from repeated observations of Jupiter using the twelve most stable KIDs from GroundBIRD array 6 (GB06). The analysis establishes and validates a calibration methodology for this detector subset while providing the first empirical characterization of detector responsivity as a function of precipitable water vapor (PWV). We find that the responsivity decreases by approximately 30% across the sampled PWV range and is well described by a linear PWV-dependent model. Comparison with Moon observations reveals distinct detector operating regimes associated with different optical loading conditions. The Jupiter-based calibration achieves better than 20% precision under typical observing conditions and better than 20% relative stability over a one-month timescale. These results establish the basis for extending the calibration methodology to the full GroundBIRD focal plane.

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GroundBIRD:在泰德天文台首次开展天空响应度标定 · 针对GroundBIRD宇宙微波背景辐射实验,利用木星观测建立了首个随水汽变化的天空响应度标定模型,标定精度优于20%且月内稳定性良好。

优先级 5 · 恒星物理

Asteroseismic forward modelling of 36 $β$ Cep pulsators and inferences on their internal differential rotation

Mathijs Vanrespaille, Dario J. Fritzewski, Vincent Vanlaer, et al.

原文摘要Abstract

Asteroseismic observations of the interior rotation of main sequence stars have shown that angular momentum transport is much more efficient than expected. Which transport mechanisms are responsible for this is still unclear. Detections of radial differential rotation provide valuable constraints on these transport mechanisms. This has been detected in several massive main sequence $β$ Cep pulsators, even though fewer than ten $β$ Cep stars have been asteroseismically modelled in detail so far. We aim to expand the sample of asteroseismically forward modelled $β$ Cep pulsators to maximally exploit their potential to observationally constrain angular momentum transport mechanisms. To that end, we seek to constrain their rotation profiles. We searched for rotational splitting of non-radial modes in a large $β$ Cep sample with identified mode degrees. These were subjected to a novel forward modelling approach, which consistently accounts for second-order rotation effects using the state-of-the-art StORM oscillation code. We successfully modelled 36 $β$ Cep stars and constrained crucial parameters such as their initial mass, internal rotation frequency, convective core mass, and age. Like in intermediate-mass main sequence stars, the internal rotation rate globally decreases in $β$ Cep stars as they evolve along the main sequence. Radial differential rotation is constrained in 17 $β$ Cep stars. The rotation rate in at least 14 stars varies by more than 10%. Of these 14 stars, ten have their rotation rate decreasing from the core to the surface while it is the opposite in four of them. We affirm that radial differential rotation is common in $β$ Cep stars. Moreover, our constrained rotation profiles suggest that the typical $β$ Cep rotation profile may be non-monotonic.

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36颗β Cep脉动星的星震学前向建模及其内部分差旋转推断 · 对36颗β Cep星进行了星震学前向建模,约束了其自转轮廓,发现径向较差旋转普遍存在且可能非单调。

优先级 5

Comparing twist-free axisymmetric gravitational waves near the black hole threshold

Ananya Adhikari, Tomáš Ledvinka, Daniela Cors, et al.

原文摘要Abstract

The threshold of black hole formation in axisymmetric vacuum gravity is proving to be more complicated than had been anticipated but, following recent advances, a consensus between independent codes and methods is emerging. Building on earlier work we provide further details of a comparison between three independent numerical codes (the bamps, prague, and sphGR codes), paying special attention to the relative strengths and weaknesses of each and examining various features of near-threshold collapse of vacuum gravitational waves for the first time. In particular, we observe quasi-universal strong-field features appearing in curvature scalars. Focusing on geometric features on the symmetry axis, we construct reference coordinates to aid the comparison of strong-field data. We evolve, for the first time, time-asymmetric wave initial data within the bamps code. To the extent possible with current methods we compare apparent horizons and attempt to determine what causes difficulties in the classification of these strong-field and highly dynamical spacetimes. In all cases the results from the three codes agree very well.

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近黑洞阈值下无扭转轴对称引力波的比较 · 本文比较了三种独立数值代码在轴对称真空引力坍缩中黑洞形成阈值附近的引力波特征,发现结果高度一致,并首次研究了时间不对称波初始数据等强场特征。

优先级 5 · 引力波 · 宇宙学

Scalar-induced gravitational waves from a box-shaped curvature power spectrum

Zu-Cheng Chen, Lang Liu

原文摘要Abstract

We compute the stochastic background of gravitational waves (GWs) produced at second order in cosmological perturbation theory by a primordial curvature power spectrum that is flat in $\ln k$ over a finite band $[k_-,k_+]=[k_*e^{-Δ},k_*e^{+Δ}]$ and vanishes elsewhere. This logarithmic box interpolates between a monochromatic spectrum as $Δ\to0$ and a locally scale-invariant plateau as $Δ\to\infty$, and its sharp boundaries make the geometry of the source convolution unusually transparent. Working in the radiation era, we reduce the convolution to a compact integral over the overlap between the momentum triangle and the box, and evaluate it analytically in two regimes. For a narrow box we show that, to leading order in the width, the spectrum equals the Dirac-spectrum result multiplied by a purely geometric overlap factor $Φ_{\rm box}(κ,Δ)$; this factor turns the infrared slope from $k^{3}\ln^{2}k$ into $k^{2}\ln^{2}k$ at a break $k_b=2k_*\sinhΔ$. For a broad box we separate the lower edge, the scale-invariant interior, and the upper edge, derive the leading behaviour in each (an infrared $k^{3}\ln^{2}k$ rise, a scale-invariant plateau, and a quartic cut-off at the hard endpoint $k=2k_+$), and combine them into a single uniform formula cast as a product of two universal, $Δ$-independent edge functions. We also provide an integral-free closed-form surrogate for these edge functions for use in parameter scans.

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盒状曲率功率谱产生的标量诱导引力波 · 该论文计算了由对数盒状原始曲率功率谱在辐射主导时期产生的二阶引力波随机背景,并给出了窄盒和宽盒情形下的解析谱表达式。

优先级 5 · 其他

Regular black holes with Minkowskian cores: causal structure and observational degeneracy

Francisco Tello-Ortiz, Y. Gómez-Leyton, Alejandro Rueda, et al.

原文摘要Abstract

We construct a new family of asymptotically flat static and rotating regular black holes characterized by a Minkowskian core and a finite two-horizon structure. The solutions are obtained within the framework of gravitational decoupling and provide an analytically tractable realization of non-singular black hole geometries with a regular interior and well-defined asymptotic properties. We investigate the optical appearance of the rotating spacetime through shadow observables and ray-traced images of geometrically thin, optically thin accretion disks. Despite the substantial differences between the interior geometry of these solutions and that of singular black holes, their optical signatures are found to remain remarkably close to those of Schwarzschild and Kerr spacetimes with the same asymptotic parameters. Our results show that markedly different black hole interiors may lead to nearly indistinguishable optical appearances, highlighting the challenges of probing the internal structure of compact objects using current shadow and imaging observations.

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具有闵可夫斯基核心的规则黑洞:因果结构与观测简并 · 构建了一类具有闵可夫斯基核心和有限双视界结构的渐近平直规则黑洞,发现其光学特征与Schwarzschild和Kerr黑洞几乎无法区分,表明当前成像观测难以探测黑洞内部结构。

优先级 5 · 食双星 · 恒星物理

Rediscussion of eclipsing binaries. Paper 32. The eccentric F-type system EY Cephei

John Southworth

原文摘要Abstract

EY Cep is a detached eclipsing binary containing two F0 V stars in an orbit with a period of 7.97 d and an eccentricity of 0.440. We determine the physical properties of the system using light-curves from the Transiting Exoplanet Survey Satellite and published spectroscopic measurements. We find masses of 1.523 +/- 0.008 Msun and 1.494 +/- 0.014 Msun, radii of 1.491 +/- 0.004 Rsun and 1.446 +/- 0.004 Rsun, and temperatures of 7070 +/- 170 K and 6990 +/- 150 K. We calculate the system's distance to be 300.3 +/- 3.8 pc, in excellent agreement with the Gaia DR3 parallax, and estimate its age to be 220 Myr. We find no evidence for pulsations, but there are hints of variation in the eclipse times potentially attributable to a third body on a longer-period eccentric orbit.

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再论食双星:第32篇:偏心F型系统EY Cephei · 利用TESS卫星光变曲线和光谱数据重新测定偏心食双星EY Cep的恒星物理参数、距离和年龄,并发现可能的第三体迹象,但未检测到脉动。

优先级 5

Corrections to inflationary models induced by non-minimal coupling between scalar field and curvature

I. V. Fomin, S. V. Chervon, E. S. Dentsel, et al.

原文摘要Abstract

In this paper, we consider possible corrections to the characteristics of inflationary models based on a specific parametrization of the non-minimal coupling between the scalar field and curvature. At the inflationary stage, these corrections lead to a deformation of the scalar field potential and a corresponding deviation in the determination of the cosmological perturbation parameters. At the same time, it is shown that the proposed parametrization yields a description of the reheating stage dynamics completely analogous to the case of Einstein gravity with minimal coupling between the scalar field and curvature. For a model-independent analysis of inflationary corrections induced by a non-minimal coupling, a classification of inflationary scenarios based on the expansion in series of the dependence of the tensor-to-scalar ratio on the spectral index of scalar perturbations is considered. It is also shown that this approach allows for the inclusion of well-known inflationary models as special cases.

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标量场与曲率非最小耦合导致的暴胀模型修正 · 本文通过参数化标量场与曲率的非最小耦合,分析了暴胀模型势能和扰动参数的修正,统一描述了再加热阶段,并提出了模型无关的分类方法,将已知暴胀模型作为特例纳入。

优先级 5 · 引力理论

Scalarization of Einstein-Euler-Heisenberg black hole with multiple horizons

Hong Guo, Yun Soo Myung

原文摘要Abstract

Scalarizations of the Einstein-Euler-Heisenberg (EEH) black hole (EEHBH) with multiple horizons are investigated in the EEH-scalar theory by introducing a quadratic scalar coupling to the Maxwell term. For mass $M=1$ and Euler-Heisenberg parameter $μ=0.03$, the magnetically charged EEHBH admits four horizon families (low, cold, negative, and hot), with triple horizons appearing in the narrow band of magnetic charge $q\in[0.95,1.0065]$. The onset scalarization around the low, cold, and high horizons is then analyzed for the magnetic charge $q=0.5,\,1,\,2$, implying infinite branches of scalarized black holes for each case. We construct the three fundamental branches of scalarized black holes. From the positivity condition of their mass, we find the upper bounds on primary scalar charges $q_{s}$ for scalarized low and cold horizons. These bounds determine the allowable regions for the Hawking temperature and entropy. Furthermore, we perform a time-domain stability analysis and find that the instabilities arise only at small scalar charge regime. Therefore, stable and physically viable scalarized black holes exist in an intermediate window of the primary scalar charge for low and cold horizon solutions and a lower bound for hot horizon solution.

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具有多个视界的爱因斯坦-欧拉-海森堡黑洞的标量化 · 研究了多视界爱因斯坦-欧拉-海森堡黑洞的标量化现象,构建了标量化黑洞的三个基本分支,并通过质量正定性条件确定了主标量电荷的上限,稳定性分析表明稳定解存在于中间窗口。

优先级 5 · 理论引力

Einstein Frame Regularization of the JNW Spacetime: From Brans-Dicke Singularity to Ellis Wormhole

A. Bhattacharya, R. N. Izmailov, R. Kh. Karimov

原文摘要Abstract

We propose a novel way to achieve the regularization of the JNW globally naked singularity sourced by the canonical Einstein minimally coupled scalar field (EMS). The key idea is to complexify (Wick rotate) the JNW parameters, which yields a regular metric that surprisingly represents a twice asymptotically flat regular traversable wormhole, famously known as the Ellis class III wormhole sourced by the ghost EMS. We begin by arguing that the JNW solution belongs to a hierarchy of actions describing different gravity theories, which indicates that a regularized version of JNW automatically adds corresponding regular versions to the hierarchy of gravity theories.

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JNW时空的爱因斯坦框架正则化:从Brans-Dicke奇点到Ellis虫洞 · 提出对JNW参数进行复杂化(Wick旋转),将全局裸奇点正则化为Ellis III类可穿越虫洞,并扩展到引力理论层级。

优先级 5 · 黑洞物理 · 测地线 · 阴影

Geodesics and shadows of the spindle-deformed Kerr black hole

Hong-Da Lyu, Mingzhi Wang, Shoulong Li

原文摘要Abstract

Recently, a new exact Ricci-flat rotating black-hole solution was constructed in four-dimensional general relativity, in which an additional parameter $B$ characterizes a spindle deformation of the Kerr geometry. We study geodesic motion and black-hole shadows in this spacetime. The Hamilton-Jacobi equation is not exactly separable for either timelike or null geodesics. Remarkably, however, at the leading nontrivial order, ${\cal O}(B^2)$, null but not timelike geodesics become separable. In the timelike sector, the spindle deformation shifts the innermost stable circular orbit and can give rise to an outermost stable circular orbit. In the null sector, exploiting the perturbatively separated equations, we analytically determine the photon region, equatorial photon orbits, and black-hole shadow, and compare the resulting predictions with direct ray tracing in the exact spacetime. The numerical results validate the perturbative treatment and quantify the deviations from Kerr.

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纺锤形变克尔黑洞的测地线与阴影 · 研究纺锤形变Kerr黑洞中的测地线运动和阴影,发现类零测地线在领头阶可分离,解析确定光子区域和阴影,数值验证与Kerr的偏离。

优先级 5 · 太阳物理 · 低相关

Radial Evolution of Near-Sun Magnetic Switchbacks Alfvenicity, Occurrence Rate, and Size

Xiaolei Li, Chen Shi, Yuliang Ding

原文摘要Abstract

Magnetic switchbacks, characterized by reversals of magnetic field direction, are widely observed in the inner heliosphere by Parker Solar Probe (PSP). With PSP reaching perihelia near 10Rs, observations from the first 24 encounters enable studies of near-Sun switchback evolution at r > 10Rs. We construct a switchback catalog within 10 < r < 55Rs by identifying magnetic field reversals with stable field magnitude and strahl-electron polarity. Statistical analysis shows that switchback Alfvenicity decreases with increasing radial distance, consistent with solar wind evolution beyond the Alfven critical point. Meanwhile, switchback occurrence rate and spatial size increase with distance, suggesting continued generation and expansion during solar wind propagation. At a given radial distance, the fraction of solar wind containing switchbacks is positively correlated with background solar wind radial velocity (VR) and Alfven Mach number (MA), while the local occurrence rate is mainly controlled by MA. These results suggest that switchback patches preferentially form in faster and higher-MA solar wind. The spatial size of switchbacks shows no clear dependence on MA or VR, implying that their size evolution is probably not determined by source conditions. Solar activity influences switchback evolution through changes in background solar wind properties, with a larger fraction of higher-MA switchbacks during solar minimum. We further identify anisotropy relative to the background magnetic field direction: the local occurrence rate and spatial size are approximately 1.5 times as large in the perpendicular direction as in the parallel direction, indicating distinct magnetic topology of switchback patches

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近太阳磁开关的径向演化:阿尔文性、发生率与尺度 · 基于帕克太阳探测器数据,统计分析了近太阳磁开关的阿尔文性(随距离减小)、发生率与空间尺度(随距离增加)的径向演化,并揭示了它们与太阳风速度、阿尔文马赫数及太阳活动周期的关联及垂直于背景磁场方向的各向异性。

优先级 0

Investigating the electron temperature of [Ar IV] in planetary nebulae using the DESIRED database

J. García-Rojas, E. Reyes-Rodríguez, J. E. Méndez-Delgado, et al.

原文摘要Abstract

(Abridged) We investigate the behaviour of the electron temperature derived from [Ar IV] lines, Te([Ar IV]), in a sample of PNe to characterize the thermal structure of high-excitation gas and compare it with the predictions of standard photoionisation models. Using the DEep Spectra of ionised REgions Data Base Extended (DESIRED-E), we selected a sample of 57 PNe for which Te([Ar IV]), Te([O III]), and ne([Ar IV]) could be determined simultaneously and homogeneously. We performed a detailed comparison between these observational diagnostics and a suite of over 160000 photoionisation models from the Mexican Million Models Database (3MdB). We find that the observed Te([Ar IV]) values are systematically higher than those predicted by pure photoionisation models for a given Te([O III]), i.e. approximately 31 percent of the PNe sample exhibits a Te([Ar IV]) more than 2sigma higher than photoionization model predictions. This discrepancy persists regardless of the specific set of auroral lines used for the diagnostic or the choice of atomic data (transition probabilities and collision strengths) adopted in the calculations. Other high-ionisation Te diagnostics, compiled from the DESIRED database or from the literature, however, do not show such behaviour, though the statistics for these are much more limited. The fact that models succeed for the highest-ionisation species but fail specifically for [Ar IV] suggests that the discrepancy is not due to a global inner-nebula heating mechanism. Instead, it points toward a localized physical effect or a limitation in the current understanding of the ionisation stratification and atomic physics specific to the Argon ion stages. This "[Ar IV] anomaly" must be resolved to ensure the reliability of abundance determinations in high-excitation nebulae.

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使用DESIRED数据库研究行星状星云中[Ar IV]的电子温度 · 该论文利用DESIRED数据库比较行星状星云中[Ar IV]电子温度的观测值与光致电离模型预测,发现前者系统偏高,揭示出“[Ar IV]异常”现象。

优先级 0 · 理论物理 · 引力理论

Nonlinear electrodynamics and stability of spherically symmetric space-times in scalar-tensor gravity

Kirill A. Bronnikov, Rustam Ibadov, Feruza Y. Shaymanova, et al.

原文摘要Abstract

We study linear perturbations of static, spherically symmetric solutions of scalar-tensor theories (STT) of gravity from the Bergmann-Wagoner-Nordtvedt class, sourced by nonlinear electrodynamics (NED). We obtain a general expression for the effective potential $V_{\rm eff}$ governing the perturbation dynamics for theories with arbitrary scalar-electromagnetic interaction of the form $L(ψ, F)$, where $ψ$ is a scalar field and $F = F_{μν} F^{μν}$ the electromagnetic invariant. This consideration includes, in particular, arbitrary scalar self-interaction potentials and scalar fields that can be phantom in some regions of space-time (the so-called trapped ghosts). Only radial (monopole) perturbations are considered here as the most likely ones to cause an instability. It is shown, in particular, that if NED has a correct Maxwell weak field limit, the zero charge limit of $V_{\rm eff}$ does not contain any trace of NED, and the perturbation dynamics is the same as for vacuum STT solutions. The previously obtained stability results for STT-Maxwell solutions are shown to be extended without change to STT-NED solutions with equal electric and magnetic charges, implying $F =0$.

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标量-张量引力中的非线性电动力学和球对称时空的稳定性 · 研究了标量-张量理论中由非线性电动力学驱动的球对称时空的线性扰动,得到了有效势的一般表达式,并证明了稳定性结果的扩展。

优先级 0

A winding number analysis of Schwarzschild black hole stability in light of Planck-scale modified kinematics

Mohsen Khodadi, Nosratolla Jafari, Shahin Mamedov

原文摘要Abstract

Determining whether Planck-scale effects can stabilize black holes addresses fundamental questions about black hole evaporation and quantum gravity consistency. Here, we analyze the thermodynamic topology of Schwarzschild black holes under Planck-scale modified kinematics, using a cubic entropy correction derived from a well-known phenomenological MDR with leading correction \(ηE^3/E_P\). Enforcing physical constraints (\(S'(r_h) > 0\), \(T > 0\)) via the entropy-geometry correspondence, we find a single unstable branch with \(w = -1\) and \(W = -1\) for both signs of the correction parameter. A second root suggesting stability (\(w = +1\)) is excluded due to negative mass/temperature and lies outside the perturbative regime. Thus, this class of MDRs does not yield stable Schwarzschild black holes. However, MDRs with different leading-order corrections may behave otherwise, leaving the search for Planck-scale stabilization an open endeavor.

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普朗克尺度修正运动学下史瓦西黑洞稳定性的缠绕数分析 · 本文利用缠绕数分析普朗克尺度修正运动学下史瓦西黑洞的稳定性,发现常见的立方修正色散关系无法产生稳定分支,而其他修正形式可能仍需探索。