用计算全息(CGH)模拟理想非球面主镜的反射波面,用补偿器对该计算全息进行检验,只要计算全息的制作误差能够满足要求,就能实现直接对补偿器的标校。介绍了计算全息标校补偿器的原理、方法,并进行了误差分析。实验采用电子束制作的计算...用计算全息(CGH)模拟理想非球面主镜的反射波面,用补偿器对该计算全息进行检验,只要计算全息的制作误差能够满足要求,就能实现直接对补偿器的标校。介绍了计算全息标校补偿器的原理、方法,并进行了误差分析。实验采用电子束制作的计算全息实现了对850 mm F/2抛物面主镜补偿器的标校,补偿器产生的标准非球面精度不低于计算全息模拟的主镜面形精度,均方根(RMS)误差为0.012λ。研究表明,用计算全息模拟主镜反射波面对补偿器进行标校是一种行之有效的方法,结合先进的微电子制造技术,可实现对补偿器的高精度标校。展开更多
The cosmic curvature Ω_(K,0),which determines the spatial geometry of the universe,is an important parameter in modern cosmology.Any deviation from Ω_(K,0)=0 would have a profound impact on the primordial inflation ...The cosmic curvature Ω_(K,0),which determines the spatial geometry of the universe,is an important parameter in modern cosmology.Any deviation from Ω_(K,0)=0 would have a profound impact on the primordial inflation paradigm and fundamental physics.In this work,we adopt a cosmological model-independent method to test whether Ω_(K,0) deviates from zero.We use the Gaussian process to reconstruct the reduced Hubble parameter E(z)and the derivative of the distance D'(z)from observational data and then determine Ω_(K,0) with a null test relation.The cosmic chronometer(CC)Hubble data,baryon acoustic oscillation(BAO)Hubble data,and supernovae Pantheon sample are considered.Our result is consistent with a spatially flat universe within the domain of reconstruction 0<z<2.3,at the 1σ confidence level.In the redshift interval 0<z<1,the result favors a flat universe,while at z>1,it tends to favor a closed universe.In this sense,there is still a possibility for a closed universe.We also carry out the null test of the cosmic curvature at 0<z<4.5 using the simulated gravitational wave standard sirens,CC+BAO,and redshift drift Hubble data.The result indicates that in the future,with the synergy of multiple highquality observations,we can tightly constrain the spatial geometry or exclude the flat universe.展开更多
文摘用计算全息(CGH)模拟理想非球面主镜的反射波面,用补偿器对该计算全息进行检验,只要计算全息的制作误差能够满足要求,就能实现直接对补偿器的标校。介绍了计算全息标校补偿器的原理、方法,并进行了误差分析。实验采用电子束制作的计算全息实现了对850 mm F/2抛物面主镜补偿器的标校,补偿器产生的标准非球面精度不低于计算全息模拟的主镜面形精度,均方根(RMS)误差为0.012λ。研究表明,用计算全息模拟主镜反射波面对补偿器进行标校是一种行之有效的方法,结合先进的微电子制造技术,可实现对补偿器的高精度标校。
基金Supported by the National SKA Program of China(2022SKA0110200,2022SKA0110203)the National Natural Science Foundation of China(11975072,11835009,11875102)。
文摘The cosmic curvature Ω_(K,0),which determines the spatial geometry of the universe,is an important parameter in modern cosmology.Any deviation from Ω_(K,0)=0 would have a profound impact on the primordial inflation paradigm and fundamental physics.In this work,we adopt a cosmological model-independent method to test whether Ω_(K,0) deviates from zero.We use the Gaussian process to reconstruct the reduced Hubble parameter E(z)and the derivative of the distance D'(z)from observational data and then determine Ω_(K,0) with a null test relation.The cosmic chronometer(CC)Hubble data,baryon acoustic oscillation(BAO)Hubble data,and supernovae Pantheon sample are considered.Our result is consistent with a spatially flat universe within the domain of reconstruction 0<z<2.3,at the 1σ confidence level.In the redshift interval 0<z<1,the result favors a flat universe,while at z>1,it tends to favor a closed universe.In this sense,there is still a possibility for a closed universe.We also carry out the null test of the cosmic curvature at 0<z<4.5 using the simulated gravitational wave standard sirens,CC+BAO,and redshift drift Hubble data.The result indicates that in the future,with the synergy of multiple highquality observations,we can tightly constrain the spatial geometry or exclude the flat universe.
