Pub Date : 2025-12-31DOI: 10.1088/1361-6382/ae2b44
Lorenzo Küchler, Geoffrey Compère, Adam Pound
The prospect of observing asymmetric compact binaries with next-generation gravitational-wave detectors has motivated the development of fast and accurate waveform models in gravitational self-force theory. These models are based on a two-stage process: in a (slow) offline stage, waveform ingredients are pre-computed as functions on the orbital phase space; in a (fast) online stage, the waveform is generated by evolving through the phase space. While this framework has traditionally been restricted to the inspiral stage of a binary, we recently extended it across the transition to plunge, where the small companion crosses the innermost stable circular orbit around the primary black hole. In this paper, for the special case of quasicircular, nonspinning binaries, we show how the ‘offline/online’ phase-space paradigm also extends through the final plunge, which generates the binary’s merger-ringdown signal. We implement the method at leading, geodesic order in the plunge. The resulting plunge waveform agrees well with a stationary-phase approximation at early times and with a (self-consistently calculated) quasinormal mode sum at late times, but we highlight that neither of the two approximations reaches the peak of the full plunge waveform. Finally, we compare the plunge waveform to numerical relativity simulations. Our framework offers the prospect of fast, accurate inspiral-merger-ringdown waveform models for asymmetric binaries.
{"title":"Self-force framework for merger-ringdown waveforms","authors":"Lorenzo Küchler, Geoffrey Compère, Adam Pound","doi":"10.1088/1361-6382/ae2b44","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2b44","url":null,"abstract":"The prospect of observing asymmetric compact binaries with next-generation gravitational-wave detectors has motivated the development of fast and accurate waveform models in gravitational self-force theory. These models are based on a two-stage process: in a (slow) offline stage, waveform ingredients are pre-computed as functions on the orbital phase space; in a (fast) online stage, the waveform is generated by evolving through the phase space. While this framework has traditionally been restricted to the inspiral stage of a binary, we recently extended it across the transition to plunge, where the small companion crosses the innermost stable circular orbit around the primary black hole. In this paper, for the special case of quasicircular, nonspinning binaries, we show how the ‘offline/online’ phase-space paradigm also extends through the final plunge, which generates the binary’s merger-ringdown signal. We implement the method at leading, geodesic order in the plunge. The resulting plunge waveform agrees well with a stationary-phase approximation at early times and with a (self-consistently calculated) quasinormal mode sum at late times, but we highlight that neither of the two approximations reaches the peak of the full plunge waveform. Finally, we compare the plunge waveform to numerical relativity simulations. Our framework offers the prospect of fast, accurate inspiral-merger-ringdown waveform models for asymmetric binaries.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"35 1","pages":"015018"},"PeriodicalIF":3.5,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-30DOI: 10.1088/1361-6382/ae2734
Qin Li, Cheng-Gang Qin, Jun Ke, Yu-Jie Tan, Jie Luo, Cheng-Gang Shao
With the rapid development of atomic clocks, the potential for gravitational-wave detection through clock comparisons emerges as a viable prospect for the future. Given the profound significance of gravitational redshift and time dilation in such comparisons, assessing its impact on gravitational wave detection with clock comparisons becomes imperative. We contemplate a two-satellite system tailored for gravitational wave detection via clock comparisons, and simulate the gravitational redshift and time dilation induced by major celestial bodies within the Solar System. Leveraging this satellite system, we conduct numerical simulations to dissect the influence of gravitational redshift and time dilation on detection sensitivity. Our analysis shows that the Sun dominates the gravitational redshift budget. In the band above 10−4 Hz, the resulting fractional frequency shift (and time dilation) spectral density is two to three orders of magnitude below 10−20/Hz, which is the target sensitivity of clock-comparison searches for gravitational waves in the millihertz band. Therefore, gravitational redshift and time dilation does not pose a notable obstacle to clock-comparison-based gravitational wave detection in frequencies above 10−4 Hz. This conclusion is also directly applicable to the frequency shifts of laser links in laser interferometric gravitational wave detection like TianQin, Taiji, and LISA.
{"title":"Effect of gravitational redshift on space-based gravitational wave detection with clock comparison","authors":"Qin Li, Cheng-Gang Qin, Jun Ke, Yu-Jie Tan, Jie Luo, Cheng-Gang Shao","doi":"10.1088/1361-6382/ae2734","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2734","url":null,"abstract":"With the rapid development of atomic clocks, the potential for gravitational-wave detection through clock comparisons emerges as a viable prospect for the future. Given the profound significance of gravitational redshift and time dilation in such comparisons, assessing its impact on gravitational wave detection with clock comparisons becomes imperative. We contemplate a two-satellite system tailored for gravitational wave detection via clock comparisons, and simulate the gravitational redshift and time dilation induced by major celestial bodies within the Solar System. Leveraging this satellite system, we conduct numerical simulations to dissect the influence of gravitational redshift and time dilation on detection sensitivity. Our analysis shows that the Sun dominates the gravitational redshift budget. In the band above <inline-formula>\u0000<tex-math><?CDATA ${10^{- 4}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2734ieqn1.gif\"></inline-graphic></inline-formula> Hz, the resulting fractional frequency shift (and time dilation) spectral density is two to three orders of magnitude below <inline-formula>\u0000<tex-math><?CDATA ${10^{- 20}}/sqrt {mathrm{Hz}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>20</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:msqrt><mml:mrow><mml:mi>Hz</mml:mi></mml:mrow></mml:msqrt></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2734ieqn2.gif\"></inline-graphic></inline-formula>, which is the target sensitivity of clock-comparison searches for gravitational waves in the millihertz band. Therefore, gravitational redshift and time dilation does not pose a notable obstacle to clock-comparison-based gravitational wave detection in frequencies above <inline-formula>\u0000<tex-math><?CDATA ${10^{- 4}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2734ieqn3.gif\"></inline-graphic></inline-formula> Hz. This conclusion is also directly applicable to the frequency shifts of laser links in laser interferometric gravitational wave detection like TianQin, Taiji, and LISA.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"28 1","pages":"015014"},"PeriodicalIF":3.5,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-30DOI: 10.1088/1361-6382/ae2c37
Tia Martineau, Francois Foucart, Mark A Scheel, Matthew D Duez, Lawrence E Kidder, Harald P Pfeiffer
In May 2023, the LIGO-Virgo-KAGRA (LVK) Collaboration reported the likely black hole-neutron star (BHNS) merger GW230529_181500. The signal was observed with high significance in only one detector, limiting constraints on the black hole spin and motivating our study of disruption in this mass regime. That event is expected to be the merger of a 2.5–4.5 <inline-formula> <tex-math><?CDATA $M_{odot}$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mrow><mml:mo>⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2c37ieqn1.gif"></inline-graphic></inline-formula> primary with a secondary compact object of mass between 1.2–2.0 <inline-formula> <tex-math><?CDATA $M_{odot}$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mrow><mml:mo>⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2c37ieqn2.gif"></inline-graphic></inline-formula>. This makes it the first BHNS merger with a significant potential for the production of electromagnetic (EM) counterparts, and provides further evidence for compact objects existing within the suspected lower mass gap. To produce post-merger EM transients, the component of the black hole spin aligned with the orbital angular momentum must be sufficiently high, allowing the neutron star to be tidally disrupted. The disrupting BHNS binary may then eject a few percent of a solar mass of matter, leading to an observable kilonova driven by radioactive decays in ejecta, and/or a compact-binary gamma-ray burst (cbGRB) resulting from the formation of an accretion disk and relativistic jet. Determining which mergers lead to disruption of the neutron star is necessary to predict the prevalence of EM signals from BHNS mergers, yet most BHNS simulations so far have been performed far from the minimum spin required for tidal disruption. Here, we use the Spectral Einstein Code to explore the behavior of BHNS mergers in a mass range consistent with GW230529_181500 close to that critical spin, and compare our results against the mass remnant model currently used by the LVK Collaboration to predict the probability of tidal disruption. Our numerical results reveal the emergence of non-zero accretion disks even below the predicted NS disruption limit, of low mass but capable of powering cbGRBs. Our results also demonstrate that the remnant mass model underpredicts the disk mass for the DD2 equation of state, while they are within expected modeling errors for SFHo. The disruption limit itself, however, is not found to significantly differ from the predictions of the analytical model, unless remnant masses <inline-formula> <tex-math><?CDATA $M_{mathrm {rem}}lesssim 0.001M_odot$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mrow><mml:mrow><mml:mi>rem</mml:mi></mml:mrow></mml:mrow></mml:msub><mml:mo>≲</mml:mo><mml:mn>0.001</mml:mn><mml:msub><mml:mi>M</mml:mi><mml:mo>⊙</mml:m
{"title":"Black hole-neutron star binaries near neutron star disruption limit in the mass regime of event GW230529","authors":"Tia Martineau, Francois Foucart, Mark A Scheel, Matthew D Duez, Lawrence E Kidder, Harald P Pfeiffer","doi":"10.1088/1361-6382/ae2c37","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2c37","url":null,"abstract":"In May 2023, the LIGO-Virgo-KAGRA (LVK) Collaboration reported the likely black hole-neutron star (BHNS) merger GW230529_181500. The signal was observed with high significance in only one detector, limiting constraints on the black hole spin and motivating our study of disruption in this mass regime. That event is expected to be the merger of a 2.5–4.5 <inline-formula>\u0000<tex-math><?CDATA $M_{odot}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mrow><mml:mo>⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2c37ieqn1.gif\"></inline-graphic></inline-formula> primary with a secondary compact object of mass between 1.2–2.0 <inline-formula>\u0000<tex-math><?CDATA $M_{odot}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mrow><mml:mo>⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2c37ieqn2.gif\"></inline-graphic></inline-formula>. This makes it the first BHNS merger with a significant potential for the production of electromagnetic (EM) counterparts, and provides further evidence for compact objects existing within the suspected lower mass gap. To produce post-merger EM transients, the component of the black hole spin aligned with the orbital angular momentum must be sufficiently high, allowing the neutron star to be tidally disrupted. The disrupting BHNS binary may then eject a few percent of a solar mass of matter, leading to an observable kilonova driven by radioactive decays in ejecta, and/or a compact-binary gamma-ray burst (cbGRB) resulting from the formation of an accretion disk and relativistic jet. Determining which mergers lead to disruption of the neutron star is necessary to predict the prevalence of EM signals from BHNS mergers, yet most BHNS simulations so far have been performed far from the minimum spin required for tidal disruption. Here, we use the Spectral Einstein Code to explore the behavior of BHNS mergers in a mass range consistent with GW230529_181500 close to that critical spin, and compare our results against the mass remnant model currently used by the LVK Collaboration to predict the probability of tidal disruption. Our numerical results reveal the emergence of non-zero accretion disks even below the predicted NS disruption limit, of low mass but capable of powering cbGRBs. Our results also demonstrate that the remnant mass model underpredicts the disk mass for the DD2 equation of state, while they are within expected modeling errors for SFHo. The disruption limit itself, however, is not found to significantly differ from the predictions of the analytical model, unless remnant masses <inline-formula>\u0000<tex-math><?CDATA $M_{mathrm {rem}}lesssim 0.001M_odot$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mrow><mml:mrow><mml:mi>rem</mml:mi></mml:mrow></mml:mrow></mml:msub><mml:mo>≲</mml:mo><mml:mn>0.001</mml:mn><mml:msub><mml:mi>M</mml:mi><mml:mo>⊙</mml:m","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"89 1","pages":"015015"},"PeriodicalIF":3.5,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-30DOI: 10.1088/1361-6382/ae2c36
Daphna Enzer, Nan Yu
We report on how to use a frequency approach to analyze Atomic Clock Ensemble in Space (ACES) space-clock to ground comparison data to constrain the gravitational-redshift violation parameter α to less than 2.9×10−6 from 12 d of simulated data. Previous work on this extrapolation achieved similar precision only with a phase approach; our method uses a frequency observable derived directly from the phase observable, avoiding the need to fit random walk data or perform Monte Carlo simulations to determine the fit uncertainty. Our approach not only results in similar α uncertainty for 12 d of simulated data but also offers new analytic expressions for how the uncertainty scales with data-length and a different framework for understanding the limits of the measurement. The new framework illustrates more readily how a 1×10−16 frequency offset between the space and ground clock leads to a bias (i.e. systematic uncertainty) in α comparable to its statistical uncertainty of 2.9×10−6. Overall, our approach provides an independent analysis method for the determining α, particularly important for the overall rigor and validity of the ACES science return.
{"title":"Frequency-analysis approach for ACES space-clock comparisons to extract gravitational redshift","authors":"Daphna Enzer, Nan Yu","doi":"10.1088/1361-6382/ae2c36","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2c36","url":null,"abstract":"We report on how to use a frequency approach to analyze Atomic Clock Ensemble in Space (ACES) space-clock to ground comparison data to constrain the gravitational-redshift violation parameter <italic toggle=\"yes\">α</italic> to less than <inline-formula>\u0000<tex-math><?CDATA $2.9{ } times { }{10^{ - 6}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mn>2.9</mml:mn><mml:mrow></mml:mrow><mml:mo>×</mml:mo><mml:mrow></mml:mrow><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>6</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2c36ieqn1.gif\"></inline-graphic></inline-formula> from 12 d of simulated data. Previous work on this extrapolation achieved similar precision only with a phase approach; our method uses a frequency observable derived directly from the phase observable, avoiding the need to fit random walk data or perform Monte Carlo simulations to determine the fit uncertainty. Our approach not only results in similar <italic toggle=\"yes\">α</italic> uncertainty for 12 d of simulated data but also offers new analytic expressions for how the uncertainty scales with data-length and a different framework for understanding the limits of the measurement. The new framework illustrates more readily how a <inline-formula>\u0000<tex-math><?CDATA $1{ } times { }{10^{ - 16}}{ }$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mn>1</mml:mn><mml:mrow></mml:mrow><mml:mo>×</mml:mo><mml:mrow></mml:mrow><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>16</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mrow></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2c36ieqn2.gif\"></inline-graphic></inline-formula> frequency offset between the space and ground clock leads to a bias (i.e. systematic uncertainty) in <italic toggle=\"yes\">α</italic> comparable to its statistical uncertainty of <inline-formula>\u0000<tex-math><?CDATA $2.9{ } times { }{10^{ - 6}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mn>2.9</mml:mn><mml:mrow></mml:mrow><mml:mo>×</mml:mo><mml:mrow></mml:mrow><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>6</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2c36ieqn3.gif\"></inline-graphic></inline-formula>. Overall, our approach provides an independent analysis method for the determining <italic toggle=\"yes\">α</italic>, particularly important for the overall rigor and validity of the ACES science return.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"53 1","pages":"015013"},"PeriodicalIF":3.5,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-30DOI: 10.1088/1361-6382/ae28ad
Zhen-Yu Heng, Jiang Long, Run-Ze Yu, Xin-Hao Zhou
We show that the helicity flux density is distinguished from magnetic helicity by analyzing Hopf solitons. The electromagnetic (EM) helicity flux and the magnetic helicity are Chern–Simons terms at different hypersurfaces. We find the helicity flux density for a point charge moving with an acceleration, extending the Liénard–Wiechert angular distribution of radiant power. We also derive the multipole expansion of the helicity flux density, generalizing the Larmor’s formula for the radiant power. These formulae have been applied to discuss the helicity flux density in several toy models such as circular and helical motion as well as soft bremsstrahlung. We also comment on the potential applications of the EM helicity flux density to pulsar systems.
{"title":"Electromagnetic helicity flux density for radiative systems","authors":"Zhen-Yu Heng, Jiang Long, Run-Ze Yu, Xin-Hao Zhou","doi":"10.1088/1361-6382/ae28ad","DOIUrl":"https://doi.org/10.1088/1361-6382/ae28ad","url":null,"abstract":"We show that the helicity flux density is distinguished from magnetic helicity by analyzing Hopf solitons. The electromagnetic (EM) helicity flux and the magnetic helicity are Chern–Simons terms at different hypersurfaces. We find the helicity flux density for a point charge moving with an acceleration, extending the Liénard–Wiechert angular distribution of radiant power. We also derive the multipole expansion of the helicity flux density, generalizing the Larmor’s formula for the radiant power. These formulae have been applied to discuss the helicity flux density in several toy models such as circular and helical motion as well as soft bremsstrahlung. We also comment on the potential applications of the EM helicity flux density to pulsar systems.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"2018 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1088/1361-6382/ae2a9d
Ivan Agullo, Béatrice Bonga, Patricia Ribes-Metidieri
We investigate the entanglement content of a free, light scalar field theory in the Bunch–Davies vacuum within the cosmological patch of de Sitter spacetime, focusing on how entanglement varies with the Hubble rate H. We find that the entanglement between any spacelike-separated pair of field modes localized in finite regions decreases as H increases. This occurs despite the fact that correlations between such local modes increase with H. Consequently, these correlations do not contribute to entanglement. Our analysis elucidates how entanglement is distributed in de Sitter space and demonstrates that localized field modes at the end of inflation are less entangled than they would be in the Minkowski vacuum of flat spacetime.
{"title":"Inflation does not create entanglement in local observables","authors":"Ivan Agullo, Béatrice Bonga, Patricia Ribes-Metidieri","doi":"10.1088/1361-6382/ae2a9d","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2a9d","url":null,"abstract":"We investigate the entanglement content of a free, light scalar field theory in the Bunch–Davies vacuum within the cosmological patch of de Sitter spacetime, focusing on how entanglement varies with the Hubble rate <italic toggle=\"yes\">H</italic>. We find that the entanglement between any spacelike-separated pair of field modes localized in finite regions <italic toggle=\"yes\">decreases</italic> as <italic toggle=\"yes\">H</italic> increases. This occurs despite the fact that correlations between such local modes <italic toggle=\"yes\">increase</italic> with <italic toggle=\"yes\">H</italic>. Consequently, these correlations do not contribute to entanglement. Our analysis elucidates how entanglement is distributed in de Sitter space and demonstrates that localized field modes at the end of inflation are less entangled than they would be in the Minkowski vacuum of flat spacetime.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"94 1","pages":"01LT01"},"PeriodicalIF":3.5,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1088/1361-6382/ae272e
Akihito Katsumata, Tomohiro Harada
We study the periapsis shift of timelike bound orbits in the equatorial plane in the Zipoy–Voorhees spacetime, which is an exact, static, axisymmetric, and vacuum solution characterized by the deformation parameter γ, including the Schwarzschild spacetime as γ = 1. We newly derive the formula for the periapsis shift by the post-Newtonian (PN) expansion and show that the quadrupole moment contributes to the periapsis shift apparently as in the 2PN order. Applying this formula to observational data on S2, a star orbiting closely to Sagittarius A* (Sgr A*), we show that the parameter γ is constrained to γ≳1.9×10−2 for the gravitational field of Sgr A*. This is equivalent to M~2≲9.7×102 in terms of the dimensionless quadrupole moment M~2, that is, the supermassive compact object at Sgr A* cannot be very prolate, whereas M~2⩾−1/3 is required from the solution. Finally, we derive a new series representation in this spacetime using a recently proposed prescription, which shows fast convergence not only in the weak-field regime with not necessarily small eccentricity but also in the strong-field regime with small eccentricity.
我们研究了Zipoy-Voorhees时空中赤道平面上类时束缚轨道的近点位移，这是一种精确的、静态的、轴对称的真空解，以变形参数γ为特征，其中史瓦西时空为γ = 1。通过后牛顿（PN）展开，我们推导出了近点位移的计算公式，并证明了四极矩对近点位移的贡献与2PN阶相似。将该公式应用于Sgr a *附近的恒星S2的观测数据，我们发现Sgr a *的引力场参数γ被限制为γ±1.9×10−2。就无量纲四极矩M~2而言，这相当于M~2 > 9.7×102，也就是说，Sgr A*上的超大质量致密物体不能非常长，而M~2小于−1/3是解决方案所需要的。最后，我们利用最近提出的一个公式，在这个时空中得到了一个新的级数表示，它不仅在不一定具有小偏心率的弱场区域，而且在具有小偏心率的强场区域也显示出快速收敛。
{"title":"Periapsis shift in the Zipoy–Voorhees spacetime","authors":"Akihito Katsumata, Tomohiro Harada","doi":"10.1088/1361-6382/ae272e","DOIUrl":"https://doi.org/10.1088/1361-6382/ae272e","url":null,"abstract":"We study the periapsis shift of timelike bound orbits in the equatorial plane in the Zipoy–Voorhees spacetime, which is an exact, static, axisymmetric, and vacuum solution characterized by the deformation parameter <italic toggle=\"yes\">γ</italic>, including the Schwarzschild spacetime as <italic toggle=\"yes\">γ</italic> = 1. We newly derive the formula for the periapsis shift by the post-Newtonian (PN) expansion and show that the quadrupole moment contributes to the periapsis shift apparently as in the 2PN order. Applying this formula to observational data on S2, a star orbiting closely to Sagittarius A* (Sgr A*), we show that the parameter <italic toggle=\"yes\">γ</italic> is constrained to <inline-formula>\u0000<tex-math><?CDATA $gamma gtrsim 1.9 times 10^{-2}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>γ</mml:mi><mml:mo>≳</mml:mo><mml:mn>1.9</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae272eieqn1.gif\"></inline-graphic></inline-formula> for the gravitational field of Sgr A*. This is equivalent to <inline-formula>\u0000<tex-math><?CDATA $tilde{M}_2 lesssim 9.7 times 10^2$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mrow><mml:mover><mml:mi>M</mml:mi><mml:mo stretchy=\"true\">~</mml:mo></mml:mover></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mo>≲</mml:mo><mml:mn>9.7</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae272eieqn2.gif\"></inline-graphic></inline-formula> in terms of the dimensionless quadrupole moment <inline-formula>\u0000<tex-math><?CDATA $tilde{M}_2$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mrow><mml:mover><mml:mi>M</mml:mi><mml:mo stretchy=\"true\">~</mml:mo></mml:mover></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae272eieqn3.gif\"></inline-graphic></inline-formula>, that is, the supermassive compact object at Sgr A* cannot be very prolate, whereas <inline-formula>\u0000<tex-math><?CDATA $tilde{M}_2 unicode{x2A7E} -1/3$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mrow><mml:mover><mml:mi>M</mml:mi><mml:mo stretchy=\"true\">~</mml:mo></mml:mover></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mtext>⩾</mml:mtext><mml:mo>−</mml:mo><mml:mn>1</mml:mn><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae272eieqn4.gif\"></inline-graphic></inline-formula> is required from the solution. Finally, we derive a new series representation in this spacetime using a recently proposed prescription, which shows fast convergence not only in the weak-field regime with not necessarily small eccentricity but also in the strong-field regime with small eccentricity.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"24 1","pages":"015012"},"PeriodicalIF":3.5,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1088/1361-6382/ae29dd
Sunil D Maharaj, Shavani Naicker, Byron P Brassel
We construct a relativistic star model with constant energy density within the framework of third order Lovelock (3OL) gravity. The 3OL field equations for a neutral fluid configuration are generated for dimensions N⩾7 in a static spherically symmetric spacetime. We investigate solutions to the field equations for isotropic fluid pressure and constant energy density. The condition of pressure isotropy generalises the general relativity and Einstein-Gauss–Bonnet equations. The unique gravitational potentials characterising the interior of constant energy density models are found explicitly in all spacetime dimensions, and contain the general relativity energy density as a limiting value. In addition, the vacuum exterior solution in 3OL gravity is generated for all spacetime dimensions. As an example we demonstrate that a complete stellar model with constant energy density can be found in 3OL gravity for the spacetime dimension N = 7 by matching at the boundary and relating the coupling constants of EGB and 3OL gravity.
{"title":"Third order Lovelock constant density model","authors":"Sunil D Maharaj, Shavani Naicker, Byron P Brassel","doi":"10.1088/1361-6382/ae29dd","DOIUrl":"https://doi.org/10.1088/1361-6382/ae29dd","url":null,"abstract":"We construct a relativistic star model with constant energy density within the framework of third order Lovelock (3OL) gravity. The 3OL field equations for a neutral fluid configuration are generated for dimensions <inline-formula>\u0000<tex-math><?CDATA $Nunicode{x2A7E}7$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>N</mml:mi><mml:mtext>⩾</mml:mtext><mml:mn>7</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae29ddieqn1.gif\"></inline-graphic></inline-formula> in a static spherically symmetric spacetime. We investigate solutions to the field equations for isotropic fluid pressure and constant energy density. The condition of pressure isotropy generalises the general relativity and Einstein-Gauss–Bonnet equations. The unique gravitational potentials characterising the interior of constant energy density models are found explicitly in all spacetime dimensions, and contain the general relativity energy density as a limiting value. In addition, the vacuum exterior solution in 3OL gravity is generated for all spacetime dimensions. As an example we demonstrate that a complete stellar model with constant energy density can be found in 3OL gravity for the spacetime dimension <italic toggle=\"yes\">N</italic> = 7 by matching at the boundary and relating the coupling constants of EGB and 3OL gravity.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"42 1","pages":"015010"},"PeriodicalIF":3.5,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1088/1361-6382/ae2bd6
Victoria Tiki, Kiet Pham, E A Huerta
Higher-order gravitational wave modes from quasi-circular, spinning, non-precessing binary-black-hole (BBH) mergers encode rich information about the nonlinear dynamics of strong-field gravity. We present a transformer-based sequence-completion surrogate that, given an early-inspiral segment, forecasts the subsequent late inspiral, merger, and ringdown. The intended applications are (i) patching or completing expensive or interrupted numerical-relativity (NR) simulations and (ii) providing late-time cross-checks and rapid hybridization studies. The training set is built from the <monospace>NRHybSur3dq8</monospace> surrogate, which provides spherical-harmonic modes up to <inline-formula> <tex-math><?CDATA $ellunicode{x2A7D}4$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:mi>ℓ</mml:mi><mml:mtext>⩽</mml:mtext><mml:mn>4</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2bd6ieqn1.gif"></inline-graphic></inline-formula> (excluding (4, 0) and <inline-formula> <tex-math><?CDATA $(4,pm1)$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mn>4</mml:mn><mml:mo>,</mml:mo><mml:mo>±</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2bd6ieqn2.gif"></inline-graphic></inline-formula>, and including (5, 5)) for mass ratios <inline-formula> <tex-math><?CDATA $qunicode{x2A7D}8$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:mi>q</mml:mi><mml:mtext>⩽</mml:mtext><mml:mn>8</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2bd6ieqn3.gif"></inline-graphic></inline-formula>, dimensionless spin components <inline-formula> <tex-math><?CDATA $s^{z}_{1,2}in[-0.8,0.8]$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:msubsup><mml:mi>s</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mn>2</mml:mn></mml:mrow><mml:mrow><mml:mi>z</mml:mi></mml:mrow></mml:msubsup><mml:mo>∈</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:mo>−</mml:mo><mml:mn>0.8</mml:mn><mml:mo>,</mml:mo><mml:mn>0.8</mml:mn><mml:mo stretchy="false">]</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2bd6ieqn4.gif"></inline-graphic></inline-formula>, and inclination angles <inline-formula> <tex-math><?CDATA $thetain[0,pi]$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:mi>θ</mml:mi><mml:mo>∈</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mi>π</mml:mi><mml:mo stretchy="false">]</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href="cqgae2bd6ieqn5.gif"></inline-graphic></inline-formula>. Waveforms are supplied on the interval <inline-formula> <tex-math><?CDATA $tin[-5000,mathrm{M},,-100,mathrm{M})$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:mi>t</mml:mi><mml:mo>∈</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:mo>−</mml:mo><mml:mn>5000</mml:mn><mml:mstyle scriptlevel="0"></mml:mstyle><mml:mrow><mml:mi mathvariant="normal">M</mml:mi></mml:mrow><mml:mo>,</mml:mo><mml:mstyle scriptlevel="
{"title":"Sequence modeling of higher-order wave modes of quasi-circular, spinning, non-precessing binary black hole mergers","authors":"Victoria Tiki, Kiet Pham, E A Huerta","doi":"10.1088/1361-6382/ae2bd6","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2bd6","url":null,"abstract":"Higher-order gravitational wave modes from quasi-circular, spinning, non-precessing binary-black-hole (BBH) mergers encode rich information about the nonlinear dynamics of strong-field gravity. We present a transformer-based sequence-completion surrogate that, given an early-inspiral segment, forecasts the subsequent late inspiral, merger, and ringdown. The intended applications are (i) patching or completing expensive or interrupted numerical-relativity (NR) simulations and (ii) providing late-time cross-checks and rapid hybridization studies. The training set is built from the <monospace>NRHybSur3dq8</monospace> surrogate, which provides spherical-harmonic modes up to <inline-formula>\u0000<tex-math><?CDATA $ellunicode{x2A7D}4$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>ℓ</mml:mi><mml:mtext>⩽</mml:mtext><mml:mn>4</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2bd6ieqn1.gif\"></inline-graphic></inline-formula> (excluding (4, 0) and <inline-formula>\u0000<tex-math><?CDATA $(4,pm1)$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mo stretchy=\"false\">(</mml:mo><mml:mn>4</mml:mn><mml:mo>,</mml:mo><mml:mo>±</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy=\"false\">)</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2bd6ieqn2.gif\"></inline-graphic></inline-formula>, and including (5, 5)) for mass ratios <inline-formula>\u0000<tex-math><?CDATA $qunicode{x2A7D}8$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>q</mml:mi><mml:mtext>⩽</mml:mtext><mml:mn>8</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2bd6ieqn3.gif\"></inline-graphic></inline-formula>, dimensionless spin components <inline-formula>\u0000<tex-math><?CDATA $s^{z}_{1,2}in[-0.8,0.8]$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msubsup><mml:mi>s</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mn>2</mml:mn></mml:mrow><mml:mrow><mml:mi>z</mml:mi></mml:mrow></mml:msubsup><mml:mo>∈</mml:mo><mml:mo stretchy=\"false\">[</mml:mo><mml:mo>−</mml:mo><mml:mn>0.8</mml:mn><mml:mo>,</mml:mo><mml:mn>0.8</mml:mn><mml:mo stretchy=\"false\">]</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2bd6ieqn4.gif\"></inline-graphic></inline-formula>, and inclination angles <inline-formula>\u0000<tex-math><?CDATA $thetain[0,pi]$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>θ</mml:mi><mml:mo>∈</mml:mo><mml:mo stretchy=\"false\">[</mml:mo><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mi>π</mml:mi><mml:mo stretchy=\"false\">]</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2bd6ieqn5.gif\"></inline-graphic></inline-formula>. Waveforms are supplied on the interval <inline-formula>\u0000<tex-math><?CDATA $tin[-5000,mathrm{M},,-100,mathrm{M})$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>t</mml:mi><mml:mo>∈</mml:mo><mml:mo stretchy=\"false\">[</mml:mo><mml:mo>−</mml:mo><mml:mn>5000</mml:mn><mml:mstyle scriptlevel=\"0\"></mml:mstyle><mml:mrow><mml:mi mathvariant=\"normal\">M</mml:mi></mml:mrow><mml:mo>,</mml:mo><mml:mstyle scriptlevel=\"","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"29 1","pages":"015009"},"PeriodicalIF":3.5,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1088/1361-6382/ae2732
Bibhash Das, Bikash Chandra Paul
We obtain traversable wormholes (TWs) in the 4D Einstein–Gauss–Bonnet (4D-EGB) gravity with phenomenological Bose–Einstein condensates (BECs) dark matter. The 4D-EGB gravity considered here results from a regularization of the higher-dimensional EGB gravity in the limit D → 4. The rescaled GB coupling parameter (α) plays an important role to admit spherically symmetric TWs. Considering the energy density profile of non-relativistic BEC matter, the shape function of the TW geometry is determined. Thereafter, all the energy conditions (ECs) namely, null EC, strong EC, weak EC, and dominant EC are analyzed for a constant redshift function. The flaring-out and asymptotic flatness conditions are probed for a realistic scenario. The embedding diagram of the TW is also analyzed along with proper radial distance, volume integral quantifier, and pressure anisotropy. TW obtained here are found stable at the throat when α=−0.0512471 with a set of model parameters, which are determined from the acceptable sound speed measurement. In the 4D EGB gravity, all the ECs are satisfied for α∈[−4.222,−4] with a set of model parameters. There is a range of α for which exotic properties of the BEC DM is not needed to sustain the TW throat, which is a new observation in modified 4D EGB gravity with BEC dark matter profile.
{"title":"Wormholes in 4D Einstein–Gauss–Bonnet gravity with BEC dark matter density profile","authors":"Bibhash Das, Bikash Chandra Paul","doi":"10.1088/1361-6382/ae2732","DOIUrl":"https://doi.org/10.1088/1361-6382/ae2732","url":null,"abstract":"We obtain traversable wormholes (TWs) in the 4D Einstein–Gauss–Bonnet (4D-EGB) gravity with phenomenological Bose–Einstein condensates (BECs) dark matter. The 4D-EGB gravity considered here results from a regularization of the higher-dimensional EGB gravity in the limit <italic toggle=\"yes\">D</italic> → 4. The rescaled GB coupling parameter (<italic toggle=\"yes\">α</italic>) plays an important role to admit spherically symmetric TWs. Considering the energy density profile of non-relativistic BEC matter, the shape function of the TW geometry is determined. Thereafter, all the energy conditions (ECs) namely, null EC, strong EC, weak EC, and dominant EC are analyzed for a constant redshift function. The flaring-out and asymptotic flatness conditions are probed for a realistic scenario. The embedding diagram of the TW is also analyzed along with proper radial distance, volume integral quantifier, and pressure anisotropy. TW obtained here are found stable at the throat when <inline-formula>\u0000<tex-math><?CDATA $alpha = - 0.051,2471$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>α</mml:mi><mml:mo>=</mml:mo><mml:mo>−</mml:mo><mml:mn>0.051</mml:mn><mml:mstyle scriptlevel=\"0\"></mml:mstyle><mml:mn>2471</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2732ieqn1.gif\"></inline-graphic></inline-formula> with a set of model parameters, which are determined from the acceptable sound speed measurement. In the 4D EGB gravity, all the ECs are satisfied for <inline-formula>\u0000<tex-math><?CDATA $alpha in [-4.222,-4]$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>α</mml:mi><mml:mo>∈</mml:mo><mml:mo stretchy=\"false\">[</mml:mo><mml:mo>−</mml:mo><mml:mn>4.222</mml:mn><mml:mo>,</mml:mo><mml:mo>−</mml:mo><mml:mn>4</mml:mn><mml:mo stretchy=\"false\">]</mml:mo></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgae2732ieqn2.gif\"></inline-graphic></inline-formula> with a set of model parameters. There is a range of <italic toggle=\"yes\">α</italic> for which exotic properties of the BEC DM is not needed to sustain the TW throat, which is a new observation in modified 4D EGB gravity with BEC dark matter profile.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"17 1","pages":"015011"},"PeriodicalIF":3.5,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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