Cosmological investigation of multi-frequency VLBI observations of ultra-compact structure in 
                
                  
                
                $$z\sim 3$$
                
                  
                    
                      z
                      ∼
                      3
                    
                  
                
               radio quasars

Cao, Shuo; Biesiada, Marek; Qi, Jing-Zhao; Pan, Yu; Zheng, Xiaogang; Xu, Tengpeng; Ji, Xuan; Zhu, Zong-Hong

doi:10.1140/epjc/s10052-018-6197-y

Cited by 31 publications

(23 citation statements)

References 44 publications

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“…However, the data for z < 0.5 are considered as unreliable because of a selection bias. Hence, ultracompact RSs themselves do not favour the ΛCDM model and the observational radio data cannot be used to effectively derive cosmological information as incorrectly claimed by Cao et al (2017) or by Cao et al (2018). Also, we can speculate that the threshold of z = 0.5, dividing biased and unbiased RSs data due to the selection effect, was chosen just for removing discrepancies between the observations and the ΛCDM model.…”

Section: Ultracompact Radio Sourcesmentioning

confidence: 97%

“…This points to the essential importance of valid D A data with z 0.6 and to the danger of reducing the analysis to data with z 0.6. If D A data are used at z 0.6 only (Cao et al 2017(Cao et al , 2018Liao 2019), the D A offset must be determined by some calibration and any information provided by the D A data is lost in this way.…”

Section: High-redshift Data (Z < 5)mentioning

confidence: 99%

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The failure of testing for cosmic opacity via the distance-duality relation

Vavryčuk

Kroupa

2020

Monthly Notices of the Royal Astronomical Society

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Abstract The distance-duality relation (DDR) between the luminosity distance DL and the angular diameter distance DA is viewed as a powerful tool for testing for the opacity of the Universe, being independent of any cosmological model. It was applied by many authors, who mostly confirm its validity and report a negligible opacity of the Universe. Nevertheless, a thorough analysis reveals that applying the DDR in cosmic opacity tests is tricky. Its applicability is strongly limited because of a non-unique interpretation of the DL data in terms of cosmic opacity and a rather low accuracy and deficient extent of currently available DA data. Moreover, authors usually assume that cosmic opacity is frequency independent and parametrize it in their tests by a prescribed phenomenological function. In this way, they only prove that cosmic opacity does not follow their assumptions. As a consequence, no convincing evidence of transparency of the universe using the DDR has so far been presented.

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Section: Ultracompact Radio Sourcesmentioning

confidence: 97%

Section: High-redshift Data (Z < 5)mentioning

confidence: 99%

The failure of testing for cosmic opacity via the distance-duality relation

Vavryčuk

Kroupa

2020

Monthly Notices of the Royal Astronomical Society

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“…Dark energy (DE) and dark matter (DM), which are the main parts of the energy content of the universe, have been firmly established by numerous astronomical and cosmological observations [1][2][3][4][5][6][7][8][9]. More specifically, the cosmic microwave background (CMB) anisotropies have verified the abundance of DM and DE with remarkable precision at (26.0 ± 0.5)% [10,11] and (68.89 ± 0.56)% [12] respectively.…”

Section: Introductionmentioning

confidence: 95%

A new way to test the WIMP dark matter models

Cheng

Diao

et al. 2021

J. High Energ. Phys.

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In this paper, we investigate the possibility of testing the weakly interacting massive particle (WIMP) dark matter (DM) models by applying the simplest phenomenological model which introduces an interaction term between dark energy (DE) and WIMP DM, i.e., Q = 3γDMHρDM. In general, the coupling strength γDE is close to 0 as the interaction between DE and WIMP DM is very weak, thus the effect of γDE on the evolution of Y associated with DM energy density can be safely neglected. Meanwhile, our numerical calculation also indicates that xf ≈ 20 is associated with DM freeze-out temperature, which is the same as the vanishing interaction scenario. As for DM relic density, it will be magnified by $$ \frac{2-3{\upgamma}_{\mathrm{DM}}}{2}{\left[2\pi {g}_{\ast }{m}_{\mathrm{DM}}^3/\left(45{s}_0{x}_f^3\right)\right]}^{\gamma_{\mathrm{DM}}} $$ 2 − 3 γ DM 2 2 π g ∗ m DM 3 / 45 s 0 x f 3 γ DM times, which provides a new way to test WIMP DM models. As an example, we analyze the case in which WIMP DM is a scalar DM. (SGL+SNe+Hz) and (CMB+BAO+SNe) cosmological observations will give γDM = $$ {0.134}_{-0.069}^{+0.17} $$ 0.134 − 0.069 + 0.17 and γDM = −0.0008 ± 0.0016, respectively. After further considering the constraints from DM direct detection experiment, DM indirect detection experiment, and DM relic density, we find that the allowed parameter space of the scalar DM model will be completely excluded for the former cosmological observations, while it will increase for the latter ones. Those two cosmological observations lead to an almost paradoxical conclusion. Therefore, one could expect more stringent constraints on the WMIP DM models, with the accumulation of more accurate cosmological observations in the near future.

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“…结合Gaussian processes处理的OHD数据可以对宇宙曲率Ω K 进行直接测量, 从而直接验证了宇宙在演化早期的平坦性 [43] . 他们还建立了多频射电类星体数据库, 其中包含单频数据库中58个中等光度类星体的多频段观测数据 [44] .…”

Section: 能量密度具有相同的数量级的事实因为λCdm理论上给出的物质密度以unclassified

“…本文采用Cao等人 [44] 从甚长基线巡天(VLBI)射电源类星体数据中提取的红移范围在0.46 < z < 2.76、 120组中等亮度的类星体角尺度-红移数据样本 [31,[34][35][36][37][38][39][40][41][42][43][44][45] 作为标准直尺限制相互作用模型. 该组数据的谱指数范围为−0.38 ≤ α ≤ 0.18, 观测亮度范围在10 27 W/Hz≤ L ≤ 10 28 W/Hz.…”

Section: 类星体数据(Qso)unclassified

Constraint on the interacting dark energy from the highly redshifted quasar data

Ming-jian

JiCheng

Pan

et al. 2020

Sci. Sin.-Phys. Mech. Astron.

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合最好的模型. (2) 相较于单独使用SNIa数据作为宇宙学标准烛光, 高红移的标准直尺QSO数据加入到SNIa里(SNIa+QSO)可以将相互作用暗能量模型参数限制得更紧密, 从而进一步证实了中等亮度类星体作为标准直尺应用到宇宙学研究中的潜力. (3) SNIa与SNIa+QSO(低红移)之间不存在冲突问题. (4) 在CMB+BAO+SNIa中引入射电类星体数据(CMB+BAO+SNIa+QSO), 我们得到的哈勃常数最佳拟合值与SNIa+QSO及CMB+BAO+SNIa 给出的结果在2σ 误差范围内保持一致, 并且进一步缓解了超新星与Planck2018给出的H 0 存在的冲突问题.

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Cosmological investigation of multi-frequency VLBI observations of ultra-compact structure in $$z\sim 3$$ z ∼ 3 radio quasars

Cited by 31 publications

References 44 publications

The failure of testing for cosmic opacity via the distance-duality relation

The failure of testing for cosmic opacity via the distance-duality relation

A new way to test the WIMP dark matter models

Constraint on the interacting dark energy from the highly redshifted quasar data

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