标题： 冷暗物质中的引力透镜时延 显示英文标题

标题： Gravitational Lens Time Delays in CDM

摘要： 在标准CDM晕轮模型中，引力透镜的时间延迟由可见星系相对于整个晕轮的冷重子质量分数f决定。 PG1115+080、SBS1520+530、B1600+434和HE2149-2745中的观测时间延迟给出的哈勃常数与HST关键项目得出的H₀=72±8 km/s Mpc一致，前提是f>0.2（单侧68%置信度），这比从CMB估计的最大值f_max=Ω_b/Ω₀=0.15±0.05更大。 如果所有可用的重子都冷却且f=f_max，则时间延迟表明H₀=65±6 km/s Mpc（95%置信度）。 如果冷重子的局部库存f=0.013/h70正确，则H₀=52±6 km/s Mpc，并且晕轮参数与等温质量模型非常吻合。 等温模型也与这些尺度上的强弱透镜研究、恒星动力学和X射线观测一致，而显著更集中的模型则不一致。 引力透镜的时间延迟、局部距离尺度和标准CDM晕轮模型之间存在冲突。 显示英文摘要

摘要： In standard CDM halo models, the time delay of a gravitational lens is determined by the cold baryon mass fraction, f, of the visible galaxy relative to the overall halo. The observed time delays in PG1115+080, SBS1520+530, B1600+434 and HE2149-2745 give Hubble constants consistent with the HST Key Project value of H0=72+/-8 km/s Mpc only if f>0.2 (1-sided 68% confidence), which is larger than the upper bound of fmax=Omega_b/Omega_0=0.15+/-0.05 estimated from the CMB. If all available baryons cool and f=fmax then the time delays imply H0=65+/-6 km/s Mpc (95% confidence). If local inventories of cold baryons, f=0.013/h70, are correct, then H0=52+/-6 km/s Mpc and the halo parameters closely match isothermal mass models. Isothermal models are also consistent with strong and weak lens studies, stellar dynamics and X-ray observations on these scales, while significantly more centrally concentrated models are not. There is a a conflict between gravitational lens time delays, the local distance scale and standard CDM halo models.