Yuewei Wen

Wedge-avoidance Fisher Forecasts for Primordial Non-Gaussianity from Dark-Ages 21-cm Power Spectrum and Bispectrum

Chen Zhang, Furen Deng, Yidong Xu, Bin Yue et autres

The Dark Ages offer a uniquely clean window on primordial physics, making the redshifted 21-cm signal a promising probe of primordial non-Gaussianity (PNG). Forecasts for interferometric 21-cm measurements must account for foreground wedge avoidance, which removes a substantial fraction of Fourier modes, …

A Designer's Guide to Lunar Far-Side Interferometer Array: Power Spectrum Measurement and Cosmological Constraints from the Dark Ages

Yuewei Wen, Bin Yue, Yidong Xu, Furen Deng et autres

The 21-cm emission line from neutral hydrogen during the cosmic Dark Ages can be a powerful probe of cosmological models and early universe physics. This work provides a quantitative forecast for the design requirements of a lunar far-side interferometer array aimed at …

Research on the Deep Peak Shaving Performance of a 600 MW Supercritical Unit After Turbine Steam-Path Retrofit

Kefeng Wang, Yanjun Li, Ling Gao, Jinhui Zhang et autres

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Probing the dark ages and cosmic dawn with 21 cm global spectrum in the DSL mission

Yidong Xu, Chuang Xu, Yuewei Wen, Junqing Xia et autres

探索宇宙黑暗时代和黎明是鸿蒙项目的重要科学目标，这主要是通过对宇宙黑暗时代和黎明时代中性氢 产生的21cm全天平均频谱（又称21cm整体谱）进行探测。利用月球轨道的优越条件，鸿蒙计划的低频子星和高频子星将分别对0.1-30MHz、30-120MHz频段的全天平均谱进行测量，而避免电离层、电磁干扰、地面反射等地面实验的常见系统误差。本文介绍了标准宇宙学模型中宇宙黑暗时代和黎明时代各种物理过程对21cm全天平均频谱形状的影响，指出可以根据测得的21cm全天平均频谱获得关于宇宙演化的重要信息。同时，也指出由于不同宇宙模型参数以及前景辐射参数的简并性，单从21cm全天平均谱观测数据对宇宙学模型的辨别能力还是有限的，需综合多种观测手段，才能获得对宇宙早期演化历史的准确认识。

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Synthesis and structure of 1′,4′-diphenyl-1a,1′,4′,4′′,5′′,9b-hexahydro-2′′ H -dispiro[cyclopropa[ l ]phenanthrene-1,2′-[1,4]epoxynaphthalene-3′,3′′-thiophene]

Yuewei Wen, Dasan M. Thamattoor

The title compound, C 39 H 30 OS, was inadvertently prepared as a Diels–Alder adduct between 1,3-diphenylisobenzofuran and 3-(1a,9b-dihydro-1 H -cyclopropa[ l ]phenanthren-1-ylidene)tetrahydrothiophene. A combination of fused, bridged, and spirocyclic ring systems are all featured within a single molecular structure of this …

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Photochemical Generation of Allenylidenes from Cyclopropanated Phenanthrenes: An Experimental and Computational Study

Alexander D. Roth, David R. Ramgren, Yuewei Wen, Megan S. Michie et autres

High Resolution Image Download MS PowerPoint Slide To address the scarcity of generally applicable photochemical routes to allenylidenes in solution, phenanthrene-based sources have been investigated. Specifically, the syntheses of 1-vinylidene-1a,9b-dihydro-1 H -cyclopropa[ l ]phenanthrene, 1-(2-phenylvinylidene)-1a,9b-dihydro-1 H -cyclopropa[ l ]phenanthrene, and 1-(2-methylvinylidene)-1a,9b-dihydro-1 H …

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Evidence for Suppression of Structure Growth in the Concordance Cosmological Model

Nhat-Minh Nguyen, Dragan Huterer, Yuewei Wen

A joint analysis of data from the CMB, weak lensing, peculiar velocities, and galaxy clustering, shows that an extension of the concordance cosmological model which includes the suppression of the growth of cosmic structure can alleviate two widely discussed cosmological tensions.

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Sweeping Horndeski canvas: new growth-rate parameterization for modified-gravity theories

Yuewei Wen, Nhat-Minh Nguyen, Dragan Huterer

Abstract We propose and numerically validate a new fitting formula that is sufficiently accurate to model the growth of structure in Horndeski theories of modified gravity for upcoming Stage IV and V large-scale structure surveys. Based on an analysis of more than …

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Sweeping Horndeski Canvas: New Growth-Rate Parameterization for Modified-Gravity Theories

Yuewei Wen, Nhat-Minh Nguyen, Dragan Huterer

We propose and numerically validate a new fitting formula that is sufficiently accurate to model the growth of structure in Horndeski theories of modified gravity for upcoming Stage IV and V large-scale structure surveys. Based on an analysis of more than 18,000 …

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Evidence for suppression of structure growth in the concordance cosmological model

Nhat-Minh Nguyen, Dragan Huterer, Yuewei Wen

We present evidence for a suppressed growth rate of large-scale structure during the dark-energy-dominated era. Modeling the growth rate of perturbations with the "growth index" γ, we find that current cosmological data strongly prefer a higher growth index than the value γ=0.55 …

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Dark Energy and Growth of Structure in Modified-Gravity Theories

Yuewei Wen

The past two decades have witnessed the emergence and flourishing of precision cosmology. Vast amount of high-quality observational data, especially those of the large scale structure and the cosmic microwave background, have been taken and analyzed. Rich information of the history, composition …

Misinterpreting modified gravity as dark energy: a quantitative study

Yuewei Wen, Eva Nesbit, Dragan Huterer, Scott Thomas Watson

Abstract Standard cosmological data analyses typically constrain simple phenomenological dark-energy parameters, for example the present-day value of the equation of state parameter, w 0, and its variation with scale factor, w a. However, results from such an analysis cannot easily indicate the …

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