检索结果-南通市图书馆

Cosmological interpretation for the stochastic signal in pulsar timing arrays

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 43-50页

作者： Yu-Mei Wu Zu-Cheng Chen qing-guo huang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Department of Physics and Synergistic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

The pulsar timing array(PTA)collaborations have recently reported compelling evidence for a stochastic signal consistent with a gravitational-wave *** this paper,we combine the latest data sets from NANOGrav,PPTA,and EPTA to explore cosmological interpretations for the PTA signal from first-order phase transitions,domain walls,and cosmic strings,*** find that the domain wall model is strongly disfavored with the Bayes factors compared with the first-order phase transitions and cosmic strings being 1/90 and 1/189,respectively,breaking the degeneracy among these models in individual data *** also find that:(1)a strong phase transition at temperatures below the electroweak scale is favored,and the bubble collisions make the dominant contribution to the energy density spectrum;(2)a small reconnection probability p<1.55×10^(-1)allowed by strings in(super)string theory is favored at the 95%confidence level,and ground-based detectors can further constrain the parameter space.

关键词： puslar timing arrays gravitational-wave background first-order phase transitions domain walls cosmic strings

同方期刊数据库

Research on light dark matter particle from evaporating primordial black hole in CDEX-10 experiment

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年

作者： qing-guo huang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study UCAS CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences

Dark matter is an essential component of the universe, accounting for approximately 85%of all matter. However,what the nature of dark matter actually is remains a huge mystery. So far, all evidence for the existence of dark matter has come from gravitational interactions. Since gravitational interactions are universal, it is challenging to reveal the nature of dark matter through gravitational interactions. To unravel the mystery of dark matter, it is essential to directly detect dark matter.

关键词：

Cosmological constraints on neutrino mass within consistent cosmological models

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第6期48卷 191-197页

作者：庞业煌张雪黄庆国 School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

Recently,the emergence of cosmological tension has raised doubts about the consistency of the ACDM *** constrain the neutrino mass within a consistent cosmological framework,we investigate three massive neutrinos with normal hierarchy(NH)and inverted hierarchy(IH)in both the axion-like early dark energy(AxiEDE)and AdS-EDE *** use joint datasets including the cosmic microwave background power spectrum from Plaanck 2018,Pantheon of type la supernova,baryon acoustic oscillation,and H0data from *** the vAxi-EDE model,we obtain∑m_(v),NH<0.152 eV and∑m_(v),IH<0.178 eV,whereas for the vAdS-EDE model,we find∑m_(v),NH<0.135 eV and∑m_(v),IH<0.167 *** results exhibit a preference for NH in both the vAxi-EDE and vAdS-EDE models.

关键词： neutrino mass cosmological tension early dark energy

Impacts of gravitational-wave background from supermassive black hole binaries on the detection of compact binaries by LISA

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第6期48卷 198-203页

作者：黄帆毕研晨曹周键黄庆国 CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Applied Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China

In the frequency band of the Laser Interferometer Space Antenna(LISA),extensive research has been conducted on the impact of foreground confusion noise generated by galactic binaries within the Milky Way ***,recent evidence of a stochastic signal,announced by the NANOGrav,EPTA,PPTA,CPTA,and InPTA,indicates that the stochastic gravitational-wave background(SGWB)generated by supermassive black hole binaries(SMBHBs)can contribute strong background noise within the LISA *** the presence of such strong noise,it is expected to have significant impacts on LISA's scientific *** this study,we investigate the impacts of the SGWB generated by SMBHBs on the detection of individual massive black hole binaries,verified galactic binaries,and extreme mass ratio inspirals in the context of *** find it essential to resolve and eliminate the excess noise from the SGWB to guarantee the success of LISA's missions.

关键词： gravitational-wave background supermassive black hole binaries LISA

Testing the first law of black hole mechanics with gravitational waves

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年

作者： Chao-Wan-Zhen Wang Jin-Bao Zhu guo-qing huang Fu-Wen Shu Department of Physics Nanchang University Center for Relativistic Astrophysics and High Energy Physics Nanchang University GCAP-CASPER Physics Department Baylor University

The successful observation of gravitational waves has provided humanity with an additional method to explore the universe, particularly black holes. In this study, we utilize data from LIGO and Virgo gravitational wave observations to test the first law of black hole mechanics, employing two different approaches. We consider the secondary compact object as a perturbation to the primary black hole before the merger, and the remnant black hole as a stationary black hole after the merger. In the pre-merger and post-merger analysis, our results demonstrate consistency with the first law, with an error level of approximate 25% at a68% credibility level for GW190403 051519. In the full inspiral-merger-ringdown analysis, our results show consistency with the first law of black hole mechanics, with an error level of about 6% at a 68% credibility level and 10% at a 95% credibility level for GW191219 163120. Additionally, we observe that the higher the mass ratio of the gravitational wave source, the more consistent our results are with the first law of black hole mechanics. Overall, our study sheds light on the nature of compact binary coalescence and their implications for black hole mechanics.

关键词：

Primordial black holes generated by the non-minimal spectator field

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2023年第8期66卷 42-50页

作者： De-Shuang Meng Chen Yuan qing-guo huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310024China

We improve and generalize the non-minimal curvaton model originally proposed in arXiv:2112.12680 to a model in which a spectator field non-minimally couples to an inflaton field and the power spectrum of the perturbation of spectator field at small scales is dramatically enhanced by the sharp feature in the form of non-minimal *** or after the end of inflation,the perturbation of the spectator field is converted into curvature perturbation and leads to the formation of primordial black holes(PBHs).Furthermore,for example,we consider three phenomenological models for generating PBHs with mass function peaked at~10^(-12) M_(⊙)and representing all the cold dark matter in our universe and find that the scalar induced gravitational waves generated by the curvature perturbation can be detected by the future space-borne gravitational-wave detectors such as Taiji,Tian Qin,and LISA.

关键词： primordial black holes non-minimal spectator field cold dark matter

Implications for the supermassive black hole binaries from the NANOGrav 15-year data set

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 3-10页

作者： Yan-Chen Bi Yu-Mei Wu Zu-Cheng Chen qing-guo huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Department of Physics and Synergistic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China

Several pulsar timing array(PTA)collaborations,including NANOGrav,EPTA,PPTA,and CPTA,have announced the evidence for a stochastic signal consistent with a stochastic gravitational wave background(SGWB).Supermassive black hole binaries(SMBHBs)are supposed to be the most promising gravitational-wave(GW)sources for this *** this paper,we use the NANOGrav 15-year data set to constrain the parameter space in an astro-informed formation model for *** results prefer a large turn-over eccentricity of the SMBHB orbit when GWs begin to dominate the SMBHB ***,the SGWB spectrum is extrapolated to the space-borne GW detector frequency band by including inspiral-merge-cutoff phases of SMBHBs,indicating that the SGWB from SMBHBs should be detected by LISA,Taiji and Tian Qin in the near future.

关键词： supermassive black hole binary gravitational wave pulsar timing array

Inflation model selection revisited

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2019年第12期62卷 28-33页

作者： Jun Li qing-guo huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

We update the constraints on the power spectra of primordial curvature perturbation and tensor perturbation including Planck data 2015(P15) and recently released BICEP2/Keck data(BK15), Baryon Acoustic Oscillation data and the Type Ia supernovae *** find that the upper limits of tensor-to-scalar ratio are 0.061, 0.064 and 0.072 at 95% confidence level(CL) in the ΛCDM+r,ΛCDM+r+αs and ΛCDM+r+αs+βs models respectively, where αsand βsare the running of scalar spectral index and running of running. The inflation model with a concave potential is favored at more than 95% CL. In addition, parametrizing the slow-roll parameter ε~ 1/N^p, where N is the e-folding number before the end of inflation and taken in the range of [50, 60] and [14, 75]respectively, we conclude that the inflation model with a monomial potential V(Ф) ~ Ф^n is disfavored at more than 95% CL, and both the Starobinsky inflation model and brane inflation model are still consistent with the data.

关键词： inflation cosmic microwave background (CMB) Baryon Acoustic Oscillation (BAO)

Measuring H0 from low-z datasets

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 2-6页

作者： Xue Zhang qing-guo huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China

The Hubble constant H0 represents the expansion rate of the Universe at present and is closely related to the age of the *** accurate measurement of Hubble constant is crucial for modern ***,different cosmological observations give diverse values of Hubble constant in *** to now,there are two methods to measure the Hubble *** is to directly measure the Hubble constant based on distance ladder estimates of Cepheids and so *** other is to globally fit the Hubble constant under the assumption of a cosmological model,for example the "standard" ACDM *** the low-redshift observational datasets,including the Pantheon sample of Type Ⅰa supernovae,baryon acoustic oscillation measurements,and the tomographic Alcock-Paczynski method,we determine the Hubble constant to be 67.95-1.03+0.78,69.81-2.70+2.22 and66.75-4.23+3.42 km s^-1 Mpc^-1 at 68% confidence level in the △CDM,wCDM and W0Wa CDM models,*** to the Hubble constant given by Riess et *** 2019,we conclude that the new physics beyond the standard △CDM model is needed if all of these datasets are reliable.

关键词： Hubble constant dark energy equation of state