A simple interferometer was used to monitor the seismic noise effect on the equivalence principle test using the free-fall interferometric method.The experimental result showed that this effect was belowλ/100,whereλ...A simple interferometer was used to monitor the seismic noise effect on the equivalence principle test using the free-fall interferometric method.The experimental result showed that this effect was belowλ/100,whereλis the wavelength of the laser beam,and the uncertainty of the differential gravity acceleration of the individual free-fall result due to this effect was about 0.6μGal.展开更多
We study a new kind of equivalence principle for rotating bodies and propose a test of the equivalence principle by comparing free-fall gravitational accelerations of two gyroscopes or a rotating and a non-rotating ex...We study a new kind of equivalence principle for rotating bodies and propose a test of the equivalence principle by comparing free-fall gravitational accelerations of two gyroscopes or a rotating and a non-rotating extended bodies.展开更多
We propose a novel scheme for a space free-fall based test of the new equivalence principle （NEP） with two rotating extended bodies made of the same material. The measurement will be carried out by placing the two c...We propose a novel scheme for a space free-fall based test of the new equivalence principle （NEP） with two rotating extended bodies made of the same material. The measurement will be carried out by placing the two concentric spinning masses of very different momenta inside a differential electrostatic aceelerometer in a drag-free compensated orbit. A difference in the forces necessary to maintain the common trajectory will be an indication of a violation of equivalence or the existence of spin-spin force between the rotating mass and the Earth. The conceptual design of the inertial sensor and its operation mode is presented. Details specific to the model and performance requirements are discussed by using up-to-date space technologies to test the NEP with an accuracy of better than 10^-15.展开更多
After inversing the x-ray surface brightness of the cooling flow cluster Abell 1689 through the isothermal β model,the isothermal double β model and the x-ray surface brightness distribution model derived from the u...After inversing the x-ray surface brightness of the cooling flow cluster Abell 1689 through the isothermal β model,the isothermal double β model and the x-ray surface brightness distribution model derived from the universal dark matter density profile,we calculate the electron distribution and the Sunyaev-Zel'dovich(SZ)effect of the cluster.The resulting temperature decrements,which are inversely proportional to the square root of H0,are very different for the three models,with uncertainty of 15%.Thus,the SZ/x-ray route can not be taken as a precise measurement of H0 until further observations(e.g.from the satellite AXAF)constrain well the amount and distribution of cluster gas.展开更多
基金Supported by the Ministry of Science and Technology of China under Grant No.95-Yu-34the National Natural Science Foundation of China under Grant No.19835040。
文摘A simple interferometer was used to monitor the seismic noise effect on the equivalence principle test using the free-fall interferometric method.The experimental result showed that this effect was belowλ/100,whereλis the wavelength of the laser beam,and the uncertainty of the differential gravity acceleration of the individual free-fall result due to this effect was about 0.6μGal.
基金Supported partially by the Ministry of Science and Technology of China under Grant No.95-Yu-34the National Natural Science Foundation of China under Grant No.19835040.
文摘We study a new kind of equivalence principle for rotating bodies and propose a test of the equivalence principle by comparing free-fall gravitational accelerations of two gyroscopes or a rotating and a non-rotating extended bodies.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61374207 and 91436107.
文摘We propose a novel scheme for a space free-fall based test of the new equivalence principle （NEP） with two rotating extended bodies made of the same material. The measurement will be carried out by placing the two concentric spinning masses of very different momenta inside a differential electrostatic aceelerometer in a drag-free compensated orbit. A difference in the forces necessary to maintain the common trajectory will be an indication of a violation of equivalence or the existence of spin-spin force between the rotating mass and the Earth. The conceptual design of the inertial sensor and its operation mode is presented. Details specific to the model and performance requirements are discussed by using up-to-date space technologies to test the NEP with an accuracy of better than 10^-15.
基金Supported by the National Natural Science Foundation of China under Grant No.19903002.
文摘After inversing the x-ray surface brightness of the cooling flow cluster Abell 1689 through the isothermal β model,the isothermal double β model and the x-ray surface brightness distribution model derived from the universal dark matter density profile,we calculate the electron distribution and the Sunyaev-Zel'dovich(SZ)effect of the cluster.The resulting temperature decrements,which are inversely proportional to the square root of H0,are very different for the three models,with uncertainty of 15%.Thus,the SZ/x-ray route can not be taken as a precise measurement of H0 until further observations(e.g.from the satellite AXAF)constrain well the amount and distribution of cluster gas.
