Research Project
Grant-in-Aid for Young Scientists (A)
We have succeeded in developing an experimental setup which can measure the difference between the speed of light propagating in opposite directions with unpreceded sensitivity. This is done by measuring the resonant frequency difference between two counterpropagating directions of an optical ring cavity. Our cavity contains a silicon piece to make the cavity asymmetric. We have developed a monolithic optical bench to reduce vibration noise and realized a continuous rotation by wireless data acquisition system. The upper limit of 5x10^{-15} to the relative difference between the speed of light propagating in opposite directions was obtained from a week-long test run. The current best limit is 5x10^{-15}, which was obtained in 2013 with a year-long data from our previous setup. We expect to improve the limit by a factor of 5 with a year-long run.
光速の等方性は光子のローレンツ不変性と結びついており、光速の異方性探査はローレンツ不変性の破れを探査していることになる。特殊相対性理論の発表から100年以上の間、様々な方法による実験的検証が世界中で行われてきたことで、ローレンツ不変性は全て物理学の基礎原理となっている。しかし、統一理論に向けた理論研究などにより、あるエネルギースケールではローレンツ不変性が破れている可能性が示唆されており、ローレンツ不変性の破れ探査実験はこれまでになく重要となっている。我々が開発に成功した実験装置はこのローレンツ不変性の破れを世界最高精度で探査することができる装置の一つである。
All 2019 2018 2017 2016 2015 Other
All Journal Article (15 results) (of which Int'l Joint Research: 12 results, Peer Reviewed: 15 results, Open Access: 10 results) Presentation (66 results) (of which Int'l Joint Research: 15 results, Invited: 8 results) Book (1 results) Remarks (1 results)
Nature Astronomy
Volume: 3 Issue: 1 Pages: 35-40
10.1038/s41550-018-0658-y
Phys. Rev. Lett.
Volume: 122 Issue: 7 Pages: 071101-071101
10.1103/physrevlett.122.071101
Classical and Quantum Gravity
Volume: 36 Issue: 9 Pages: 95015-95015
10.1088/1361-6382/ab0fcb
Living Reviews in Relativity
Volume: 21 Issue: 1 Pages: 3-3
10.1007/lrr-2016-1
Phys. Rev. D
Volume: 97 Issue: 10 Pages: 102001-102001
10.1103/physrevd.97.102001
Volume: 97 Issue: 10 Pages: 104003-104003
10.1103/physrevd.97.104003
International Journal of Modern Physics D
Volume: 27 Issue: 12 Pages: 1845001-1845001
10.1142/s0218271818450013
Volume: 97 Issue: 12 Pages: 122003-122003
10.1103/physrevd.97.122003
Volume: 98 Issue: 2 Pages: 22008-22008
10.1103/physrevd.98.022008
130007735273
Volume: 121 Issue: 16 Pages: 161301-161301
10.1103/physrevlett.121.161301
Optics Express
Volume: 25 Issue: 12 Pages: 13799-13799
10.1364/oe.25.013799
130007510803
Volume: 34 Issue: 22 Pages: 225001-225001
10.1088/1361-6382/aa90e3
Proceedings of the Fourteenth Marcel Grossmann Meeting
Volume: 0
Progress of Theoretical and Experimental Physics
Volume: 2018 Issue: 1 Pages: 1-23
10.1093/ptep/ptx180
Physics Review A
Volume: 94 Issue: 3 Pages: 033822-033822
10.1103/physreva.94.033822
http://granite.phys.s.u-tokyo.ac.jp/michimura/wiki/