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Constraints on brane inflation after Planck 2015: Impacts of the latest local measurement of the Hubble constant

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Science China(Physics,Mechanics & Astronomy) 2019年第3期62卷 41-48页

作者： rui-yun guo Lei Zhang Jing-Fei Zhang Xin Zhang Department of Physics College of Sciences Northeastern University Center for High Energy Physics Peking University

We investigate the observational constraints on three typical brane inflation models by considering the latest local measurement of the Hubble constant in the global fit. We also employ other observational data, including the Planck 2015 CMB data, the BICEP2/Keck Array B-mode data, and the baryon acoustic oscillations data, in our analysis. Previous studies have shown that the addition of the latest local H_0 measurement favors a larger spectral index, and can exert a significant influence on the model selection of inflation. In this work, we investigate its impacts on the status of brane inflation models. We find that, when the direct H_0 measurement is considered, the prototype model of brane inflation is still in good agreement with the current observational data within the 2σ level range. For the KKLMMT model, the consideration of the H_0 measurement allows the range of the parameter β to be amplified to O(10^(-2)), which slightly alleviates the fine-tuning problem. For the IR DBI model, the addition of the H_0 measurement does not provide a better fit. These results show that the consideration of the new H_0 prior can exert a considerable influence on the brane inflation models. At last, we show that, when β≤1.1, the equilateral non-Gaussianity in the IR DBI inflation model is compatible with the current CMB data at the 1σ level.

关键词： brane inflation inflationary cosmology observational constraints

Exploring neutrino mass and mass hierarchy in the scenario of vacuum energy interacting with cold dark matte

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Chinese Physics C 2018年第9期42卷 115-124页

作者： rui-yun guo Jing-Fei Zhang Xin Zhang Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center for High Energy Physics Peking UniversityBeijing 100080China

We investigate the constraints on total neutrino mass in the scenario of vacuum energy interacting with cold dark matter. We focus on two typical interaction forms, i.e., Q=βHρc and Q=βHρΛ. To avoid the occurrence of large-scale instability in interacting dark energy cosmology, we adopt the parameterized post-Friedmann approach to calculate the perturbation evolution of dark energy. We employ observational data, including the Planck cosmic microwave background temperature and polarization data, baryon acoustic oscillation data, a JLA sample of type Ia supernovae observation, direct measurement of the Hubble constant, and redshift space distortion data. We find that, compared with those in the ΛCDM model, much looser constraints onstraints are obtained in the Q=βHρΛ mode mν are obtained in the Q = βHρc model, whereas slightly tighter conl. Consideration of the possible mass hierarchies of neutrinos reveals that the smallest upper limit ofarchy mν appears in the degenerate hierarchy case. By comparing the values of χ~2 min, we find that the normal hiercase is favored over the inverted one. In particular,we find that the difference ？χ22 min ≡χIH;min-χ~2 NH;min〉 2 in the Q = βHρc model. In addition, we find that β = 0 is consistent with the current observations in the Q=βHρc model, and β 〈0 is favored at more than the 1σ level in the Q=βHρΛ model.

关键词： interacting dark energy neutrino mass mass hierarchy of neutrinos parameterized post-Friedmannapproach cosmological observations

Redshift drift constraints on f（T） gravity

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Frontiers of physics 2015年第5期10卷 1-6页

作者： Jia-Jia Geng rui-yun guo Dong-Ze He Jing-Fei Zhang Xin Zhang Department of Physics College of Sciences Northeastern University Shenyang 110004 China Center for High Energy Physics Peking University Beijing 100080 China

We explore the impact of the Sandage-Loeb （SL） test on the precision of cosmological constraints for f（T） gravity theories. The SL test is an important supplement to current cosmological observations because it measures the redshift drift in the Lyman-α forest in the spectra of distant quasars, covering the ＂redshift desert＂ of 2 ≤ z ≤ 5. To avoid data inconsistency, we use the best-fit models based on current combined observational data as fiducial models to simulate 30 mock SL test data. We quantify the impact of these SL test data on parameter estimation for f（T） gravity theories. Two typical f（T） models are considered, the power-law model f（T）pL and the exponential-form model f（T）Exp. The results show that the SL test can effectively break the existing strong degeneracy between the present-day matter density Ωm and the Hubble constant Ho in other cosmological observations. For the considered f（T） models, a 30-year observation of the SL test can improve the constraint precision of Ωm and H0 enormously but cannot effectively improve the constraint precision of the model parameters.

关键词： redshift drift cosmological constraints dark energy modified gravity f(T) gravity

The Synthesis of α-DDB, β-DDB and Theoretical Study with AM1

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Chinese Chemical Letters 2001年第6期12卷 491-494页

作者： rui yun guo Jun Biao CHANG Rong Feng CHEN Jing Xi XIE Da Yu YAN Henan Institute of Chemistry Zhengzhou 450002 Institute of Meteria Medica Chinese Academy of Medical ScienceBeijing 100050 The Graduate School of University of Science and Technology of China Beijing 100039

The present paper reports the synthesis of two analogs of Schzandrin C (-DDB, (-DDB with the gallic acid as the starting material. The key step is the synthesis of monomer of (-DDB and (-DDB for coupling. (-DDB, (-DDB have different yields in Ullmann coupling reaction under the same condition. The yield of (-DDB is little lower than that of (-DDB. The AM1 calculation demonstrates that ΔH of the Ullmann coupling reaction of (-DDB and (-DDB are different. The former is -175.76966KJ/mol and the later is -203.21246KJ/mol. This is in agreement with the fact that (-DDB has higher yield than (-DDB.

关键词： Analogs of Schzandrin C biphenyl dimenthoxy dicarboxylate biphenyl AM1 calculation

Prospect for Cosmological Parameter Estimation Using Future Hubble Parameter Measurements

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Communications in Theoretical Physics 2018年第10期70卷 445-450页

作者： Jia-Jia Geng rui-yun guo An-Zhong Wang Jing-Fei Zhang Xin Zhang Institute for Advanced Physics & Mathematics Zhejiang University of Technology Hangzhou 310032 China Department of Physics College of Sciences Northeastern University Shenyang 110004 China GCAP-CASPER Department of Physics Baylor University Waco TX 76798-7316 USA Center for High Energy Physics Peking University Beijing 100080 China Center for Gravitation and Cosmology Yangzhou University Yangzhou 225009 China

We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological parameters using 52 current Hubble parameter data including the Hubble constant measurement from the Hubble Space Telescope. Then we simulate the baryon acoustic oscillation signals from WFIRST(Wide-Field Infrared Survey Telescope) covering the redshift range of z ∈ [0.5, 2] and the redshift drift data from E-ELT(European Extremely Large Telescope) in the redshift range of z ∈ [2, 5]. It is shown that solely using the current Hubble parameter data could give fairly good constraints on cosmological parameters. Compared to the current Hubble parameter data, with the WFIRST observation the H(z) constraints on dark energy would be improved slightly, while with the E-ELT observation the H(z) constraints on dark energy is enormously improved.

关键词： dark energy cosmological parameter constraints Hubble parameter measurements

Constraining Neutrino Mass in Dynamical Dark Energy Cosmologies with the Logarithm Parametrization and the Oscillating Parametrization

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Journal of High Energy Physics, Gravitation and Cosmology 2023年第4期9卷 1044-1061页

作者： Tian-Ying Yao rui-yun guo Xin-Yue Zhao School of Sciences Xi’an Technological University Xi’an China

We constrain two dynamical dark energy models that are parametrized by the logarithm form of and the oscillating form of . Comparing with the Chevallier-Polarski-Linder (CPL) model, the two parametrizations for dark energy can explore the whole evolution history of the universe properly. Using the current mainstream observational data including the cosmic microwave background data and the baryon acoustic oscillation data as well as the type Ia supernovae data, we perform the X2 statistic analysis to global fit these models, finding that the logarithm parametrization and the oscillating parameterization are almost as well as the CPL scenario in fitting these data. We make a comparison for the impacts of the dynamical dark energy on the cosmological constraints on the total mass of active neutrinos. We find that the logarithm parametrization and the oscillating parameterization can increase the fitting values of Σmv. Looser constraints on Σmv are obtained in the logarithm and oscillating models than those derived in the CPL model. Consideration of the possible mass ordering of neutrinos reveals that the most stringent constraint on Σmv appears in the degenerate hierarchy case.

关键词： Dynamical Dark Energy Neutrino Mass Observational Constraints

A Facile Synthesis of β-Cyclodextrin Monoaldehyde

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Chinese Chemical Letters 1999年第4期10卷 273-274页

作者： Jing HU Cheng Feng YE Yong De ZHAO Jun Biao CHANG rui yun guo(Lanzhou Institute of Chemical Physics, Chinese Academy of Scences Lanzhou 730000)(Henan Institute of Chemistry, Zhengzhou 450002) Lanzhou Inst. of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China Henan Institute of Chemistry Zhengzhou 450002 China

β -Cyclodextrin (β -CD) was directly oxidized in high yield to the corresponding monoaldehyde by cyclized 2-iodoxybenzoic acid (IBX) in DMSO.

关键词： Cyclodextrin oxidant aldehyde

The detection, extraction and parameter estimation of extreme-mass-ratio inspirals with deep learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 86-96页

作者： Qianyun yun Wen-Biao Han Yi-Yang guo He Wang Minghui Du Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Shanghai Jiao Tong University School of Astronomy and Space Science University of Chinese Academy of Sciences Taiji Laboratory for Gravitational Wave Universe (Beijing/Hangzhou) University of Chinese Academy of Sciences Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Province Key Laboratory of Quantum Theory and Applications of MoE Lanzhou University Institute of Theoretical Physics & Research Center of Gravitation Lanzhou University International Centre for Theoretical Physics Asia-Pacific (ICTP-AP) University of Chinese Academy of Sciences (UCAS) Center for Gravitational Wave Experiment National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences

One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EMRIs). This task is particularly challenging because EMRI signals are complex, lengthy, and faint. In this work, we introduce a2-layer convolutional neural network(CNN) approach to detect EMRI signals for space-borne detectors, achieving a true positive rate(TPR) of 96.9% at a 1% false positive rate(FPR) for signal-to-noise ratio(SNR) from 50 to 100. Especially, the key intrinsic parameters of EMRIs such as the mass, spin of the supermassive black hole(SMBH) and the initial eccentricity of the orbit can also be inferred directly by employing a neural network. The mass and spin of the SMBH can be determined at 99% and 92% respectively. This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter *** model also has a low dependency on the accuracy of the waveform model. This study underscores the potential of deep learning methods in EMRI data analysis, enabling the rapid detection of EMRI signals and efficient parameter estimation.

关键词： gravitational wave EMRIs deep-learing

The linear self-attracting diffusion driven by the weighted-fractional Brownian motion II: The parameter estimation

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Science China Mathematics 2025年

作者： Litan Yan rui guo Wenyi Pei Department of Statistics College of Science Donghua University School of Statistics and Mathematics Zhejiang Gongshang University

Let Ba,bbe a weighted-fractional Brownian motion with Hurst indexes a and b such that a>-1and 0≤b<1∧（1+a）.In this paper,we consider the linear self-attracting diffusion ■ interacting diffusion (see Cranston and Le Jan （1995）).Under the continuous observation,we study asymptotic ■ converges in distribution to the sum of the chi-square random variable with 1 degree of freedom and the random variable Z1a,b.

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