![Keiko Kokeyama BSc, MSc, PhD, FHEA](https://profiles-cardiff.imgix.net/attachments/4420?w=200&h=200&auto=format&crop=faces&fit=crop&q=90")
Dr Keiko Kokeyama
(she/her)
BSc, MSc, PhD, FHEA
Senior Lecturer
Gravity Exploration Institute
- Available for postgraduate supervision
Overview
I am an experimental physicist in gravitational-wave detector science. Since the monumental first detection of gravitational waves from a binary black hole merger in 2015, followed by a neutron star merger in 2017, it has been a golden age of gravitational-wave astrophysics. The gravitational wave detectors are laser interferometers to detect distortions of space-time caused by gravitational waves, coming from somewhere in the universe. Because the distortions of space-time are extremely small, typically an order of 10^(-21) m (0.000...21 zeros... 001 m, one-millionth of a proton diameter), the gravitational-wave detectors are extremely sensitive, as precise as Heisenberg's uncertainty limit allows. I worked on the two large-scale detectors, LIGO Livingston detector and KAGRA detector to make the detector work and improve the sensitivity to run the astrophysical observations. Because the instruments must be very sensitive, many state-of-the-art technologies are being developed and implemented. Currently, at Cardiff, I work on new technologies to make future detectors more sensitive. We want to observe more numbers of black hole or neutron star mergers from even the father universe.
Publication
2024
- Abac, A. G. et al. 2024. A search using GEO600 for gravitational waves coincident with fast radio bursts from SGR 1935+2154. The Astrophysical Journal 977(2), article number: 255. (10.3847/1538-4357/ad8de0)
- Wang, H. et al. 2024. Characterization of birefringence inhomogeneity of KAGRA sapphire mirrors from transmitted wavefront error measurements. Physical Review D (particles, fields, gravitation, and cosmology) 110(8), article number: 82007. (10.1103/physrevd.110.082007)
- Abac, A. G. et al. 2024. Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo. The Astrophysical Journal 973(2), article number: 132. (10.3847/1538-4357/ad65ce)
- Abac, A. et al. 2024. Ultralight vector dark matter search using data from the KAGRA O3GK run. Physical Review D (particles, fields, gravitation, and cosmology) 110(4), article number: 42001. (10.1103/physrevd.110.042001)
- Abbott, R. et al. 2024. Search for gravitational-lensing signatures in the full third observing run of the LIGO–Virgo network. Astrophysical Journal 970(191) (10.3847/1538-4357/ad3e83)
- Abac, A. G. et al. 2024. Observation of gravitational waves from the coalescence of a 2.5–4.5 M ⊙ compact object and a neutron star. The Astrophysical Journal Letters 970(2), article number: L34. (10.3847/2041-8213/ad5beb)
- Abbott, R. et al. 2024. Search for gravitational-wave transients associated with magnetar bursts in Advanced LIGO and Advanced Virgo data from the third observing run. The Astrophysical Journal 966(1), article number: 137. (10.3847/1538-4357/ad27d3)
- Fletcher, C. et al. 2024. A joint Fermi-GBM and Swift-BAT analysis of Gravitational-wave candidates from the third Gravitational-wave Observing Run. The Astrophysical Journal 964(2), article number: 149. (10.3847/1538-4357/ad1eed)
- Sakai, Y. et al. 2024. Training process of unsupervised learning architecture for gravity spy dataset. Annalen der Physik 536(2), article number: 2200140. (10.1002/andp.202200140)
2023
- Abbott, R. et al. 2023. Open Data from the Third Observing Run of LIGO, Virgo, KAGRA, and GEO. Astrophysical Journal Supplement 267(2), article number: 29. (10.3847/1538-4365/acdc9f)
- Abbott, R. et al. 2023. Constraints on the cosmic expansion history from GWTC–3. Astrophysical Journal 949(2), article number: 76. (10.3847/1538-4357/ac74bb)
- Abe, H. et al. 2023. Noise subtraction from KAGRA O3GK data using Independent Component Analysis. Classical and Quantum Gravity 40(8), article number: 85015. (10.1088/1361-6382/acc0cb)
- Akutsu, T. et al. 2023. Input optics systems of the KAGRA detector during O3GK. Progress of Theoretical and Experimental Physics 2023(2), article number: 023F01. (10.1093/ptep/ptac166)
2022
- Abbott, R. et al. 2022. Model-based cross-correlation search for gravitational waves from the low-mass x-ray binary scorpius x-1 in ligo o3 data. Astrophysical Journal Letters 941(2), article number: L30. (10.3847/2041-8213/aca1b0)
- Fairhurst, S. et al. 2022. All-sky search for continuous gravitational waves from isolated neutron stars using Advanced LIGO and Advanced Virgo O3 data. Physical Review D 106(10) (10.1103/PhysRevD.106.102008)
- Abe, H. et al. 2022. Performance of the KAGRA detector during the first joint observation with GEO 600 (O3GK). Progress of Theoretical and Experimental Physics, article number: ptac093. (10.1093/ptep/ptac093)
- Abe, H. et al. 2022. The current status and future prospects of KAGRA, the large-scale cryogenic gravitational wave telescope built in the Kamioka underground. Galaxies 10(3), article number: 63. (10.3390/galaxies10030063)
- Sakai, Y. et al. 2022. Unsupervised learning architecture for classifying the transient noise of interferometric gravitational-wave detectors. Scientific Reports 12(1), article number: 9935. (10.1038/s41598-022-13329-4)
- Abbott, R. et al. 2022. Searches for gravitational waves from known pulsars at two harmonics in the second and third LIGO-Virgo observing runs. Astrophysical Journal 935(1), article number: 1. (10.3847/1538-4357/ac6acf)
- Abbott, R. et al. 2022. Search for gravitational waves associated with gamma-ray bursts detected by Fermi and Swift during the LIGO-Virgo Run O3b. Astrophysical Journal 928(2), article number: 186. (10.3847/1538-4357/ac532b)
- Abbott, R. et al. 2022. Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo. Astronomy & Astrophysics 659, article number: A84. (10.1051/0004-6361/202141452)
- Abbott, R. et al. 2022. Constraints on dark photon dark matter using data from LIGO's and Virgo's third observing run. Physical Review D 105(6), article number: 63030. (10.1103/PhysRevD.105.063030)
2021
- Abbott, R. et al. 2021. All-sky search for short gravitational-wave bursts in the third Advanced LIGO and Advanced Virgo run. Physical Review D 104, article number: 122004. (10.1103/PhysRevD.104.122004)
- Akutsu, T. et al. 2021. Overview of KAGRA: Calibration, detector characterization, physical environmental monitors, and the geophysics interferometer. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A102. (10.1093/ptep/ptab018)
- Kawamura, S. et al. 2021. Current status of space gravitational wave antenna DECIGO and B-DECIGO. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A105. (10.1093/ptep/ptab019)
- Akutsu, T. et al. 2021. Overview of KAGRA: KAGRA science. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A103. (10.1093/ptep/ptaa120)
- Akutsu, T. et al. 2021. Overview of KAGRA: Detector design and construction history. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A101. (10.1093/ptep/ptaa125)
- Akutsu, T. et al. 2021. Radiative cooling of the thermally isolated system in KAGRA gravitational wave telescope. Journal of Physics: Conference Series 1857(1), article number: 12002. (10.1088/1742-6596/1857/1/012002)
2020
- Yamada, R. et al. 2020. Optimization of quantum noise by completing the square of multiple interferometer outputs in quantum locking for gravitational wave detectors. Physics Letters A 384(26), article number: 126626. (10.1016/j.physleta.2020.126626)
- Abbott, B. P. et al. 2020. Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA. Living Reviews in Relativity 23(1), article number: 3. (10.1007/s41114-020-00026-9)
- Zhu, Z. -. et al. 2020. Application of independent component analysis to the iKAGRA data. Progress of Theoretical and Experimental Physics 2020(5), article number: 053F01. (10.1093/ptep/ptaa056)
- Akutsu, T. et al. 2020. An arm length stabilization system for KAGRA and future gravitational-wave detectors. Classical and Quantum Gravity 37(3), article number: 35004. (10.1088/1361-6382/ab5c95)
2019
- Yamamoto, K. et al. 2019. Design and experimental demonstration of a laser modulation system for future gravitational-wave detectors. Classical and Quantum Gravity 36(20), article number: 205009. (10.1088/1361-6382/ab4489)
- Akiyama, Y. et al. 2019. Vibration isolation system with a compact damping system for power recycling mirrors of KAGRA. Classical and Quantum Gravity 36(9), article number: 95015. (10.1088/1361-6382/ab0fcb)
- KAGRA collaboration, . and Kokeyama, K. 2019. KAGRA: 2.5 generation interferometric gravitational wave detector. Nature Astronomy 3(1), pp. 35-40. (10.1038/s41550-018-0658-y)
2018
- Kokeyama, K. et al. 2018. Demonstration for a two-axis interferometric tilt sensor in KAGRA. Physics Letters A 382(29), pp. 1950-1955. (10.1016/j.physleta.2018.05.004)
- Akutsu, T. et al. 2018. Construction of KAGRA: an underground gravitational-wave observatory. Progress of Theoretical and Experimental Physics 2018(1), article number: 013F01. (10.1093/ptep/ptx180)
2016
- Abbott, B. P. et al. 2016. GW150914: the advanced LIGO detectors in the era of first discoveries. Physical Review Letters 116(13), article number: 131103. (10.1103/PhysRevLett.116.131103)
- Abbott, B. P. et al. 2016. Astrophysical implications of the binary black hole merger GW150914. Astrophysical Journal Letters 818(2), article number: L22. (10.3847/2041-8205/818/2/L22)
- Abbott, B. P. et al. 2016. Observation of gravitational waves from a binary black hole merger. Physical Review Letters 116(6), article number: 61102. (10.1103/PhysRevLett.116.061102)
- Mueller, C. L. et al. 2016. The advanced LIGO input optics. Review of Scientific Instruments 87(1), article number: 14502. (10.1063/1.4936974)
2015
- Evans, M. et al. 2015. Observation of Parametric Instability in Advanced LIGO. Physical Review Letters 114(16), article number: 161102. (10.1103/PhysRevLett.114.161102)
2014
- Staley, A. et al. 2014. Achieving resonance in the advanced LIGO gravitational-wave interferometer. Classical and Quantum Gravity 31(24), article number: 245010. (10.1088/0264-9381/31/24/245010)
- Kokeyama, K., Izumi, K., Korth, W. Z., Smith-Lefebvre, N., Arai, K. and Adhikari, R. X. 2014. Residual amplitude modulation in interferometric gravitational wave detectors. Journal of the Optical Society of America A 31(1), pp. 81-88. (10.1364/JOSAA.31.000081)
2013
- Lodhia, D., Brown, D., Brückner, F., Carbone, L., Fulda, P., Kokeyama, K. and Freise, A. 2013. Interferometer phase noise due to beam misalignment on diffraction gratings. Optics Express 21(24), pp. 29578-29591. (10.1364/OE.21.029578)
2012
- Fulda, P. et al. 2012. Review of the Laguerre-Gauss mode technology research program at Birmingham. Presented at: 9th Edoardo Amaldi Conference and Numerical Relativity - Data Analysis Meeting (Amaldi 9/NRDA 2011), Cardiff, Wales, 10-15 July 2011, Vol. 363. IOP Publishing: Conference Series pp. 12010., (10.1088/1742-6596/363/1/012010)
2011
- Bond, C., Fulda, P., Carbone, L., Kokeyama, K. and Freise, A. 2011. Higher order Laguerre-Gauss mode degeneracy in realistic, high finesse cavities. Physical Review D - Particles, Fields, Gravitation and Cosmology 84(10), article number: 102002. (10.1103/PhysRevD.84.102002)
2010
- Somiya, K., Kokeyama, K. and Nawrodt, R. 2010. Remarks on thermoelastic effects at low temperatures and quantum limits in displacement measurements. Physical Review D, Particles and fields 63(8), article number: 127101. (10.1103/PHYSREVD.82.127101)
- Fulda, P., Kokeyama, K., Chelkowski, S. and Freise, A. 2010. Experimental demonstration of higher-order Laguerre-Gauss mode interferometry. Physical Review D - Particles, Fields, Gravitation and Cosmology 82(1), article number: 12002. (10.1103/PhysRevD.82.012002)
2009
- Kokeyama, K., Sato, S., Nishizawa, A., Kawamura, S., Chen, Y. and Sugamoto, A. 2009. Development of a displacement- and frequency-noise-free interferometer in a 3D configuration for gravitational wave detection. Physical Review Letters 103, article number: 171101. (10.1103/PhysRevLett.103.171101)
2008
- Kokeyama, K., Somiya, K., Kawazoe, F., Sato, S., Kawamura, S. and Sugamoto, A. 2008. Development of a signal-extraction scheme for resonant sideband extraction. Classical and Quantum Gravity 25(23), article number: 235013. (10.1088/0264-9381/25/23/235013)
- Sato, S. et al. 2008. Demonstration of displacement-noise-free interferometry using bi-directional Mach-Zehnder interferometers. Classical and Quantum Gravity 25(11), article number: 114031. (10.1088/0264-9381/25/11/114031)
- Kokeyama, K. et al. 2008. The experimental plan of displacement- and frequency-noise free laser interferometer. Presented at: The Seventh Edoardo Amaldi Conference On Gravitational Waves (amaldi7), Sydney, Australia, 8-14 July 2007, Vol. 122. IOP Publishing: Conference Series, (10.1088/1742-6596/122/1/012022)
2007
- Sato, S., Kawamura, S., Kokeyama, K., Kawazoe, F. and Somiya, K. 2007. Diagonalization of the length sensing matrix of a dual recycled laser interferometer gravitational wave antenna. Physical Review D - Particles, Fields, Gravitation and Cosmology 75(8), article number: 82004. (10.1103/PhysRevD.75.082004)
- Sato, S., Kokeyama, K., Ward, R. L., Kawamura, S., Chen, Y., Pai, A. and Somiya, K. 2007. Demonstration of displacement- and frequency-noise-free laser interferometry using bidirectional Mach-Zehnder Interferometers. Physical Review Letters 98(14), article number: 141101. (10.1103/PhysRevLett.98.141101)
2006
- Chen, Y. et al. 2006. Interferometers for displacement-noise-free gravitational-wave detection. Physical Review Letters 97(15), article number: 151103. (10.1103/PhysRevLett.97.151103)
- Kokeyama, K., Sato, S., Kawazoe, F., Somiya, K., Fukushima, M., Kawamura, S. and Sugamoto, A. 2006. Downselect of the signal extraction scheme for LCGT. Journal of Physics: Conference Series 32, article number: 65. (10.1088/1742-6596/32/1/065)
- Kawazoe, F. et al. 2006. The experimental plan of the 4m resonant sideband extraction prototype for the LCGT. Journal of Physics: Conference Series 32, pp. 380-385., article number: 58. (10.1088/1742-6596/32/1/058)
- Sato, S., Kokeyama, K., Kawazoe, F., Somiya, K. and Kawamura, S. 2006. Diagonalizing sensing matrix of broadband RSE. Journal of Physics: Conference Series 32, pp. 470-475., article number: 72. (10.1088/1742-6596/32/1/072)
Articles
- Abac, A. G. et al. 2024. A search using GEO600 for gravitational waves coincident with fast radio bursts from SGR 1935+2154. The Astrophysical Journal 977(2), article number: 255. (10.3847/1538-4357/ad8de0)
- Wang, H. et al. 2024. Characterization of birefringence inhomogeneity of KAGRA sapphire mirrors from transmitted wavefront error measurements. Physical Review D (particles, fields, gravitation, and cosmology) 110(8), article number: 82007. (10.1103/physrevd.110.082007)
- Abac, A. G. et al. 2024. Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo. The Astrophysical Journal 973(2), article number: 132. (10.3847/1538-4357/ad65ce)
- Abac, A. et al. 2024. Ultralight vector dark matter search using data from the KAGRA O3GK run. Physical Review D (particles, fields, gravitation, and cosmology) 110(4), article number: 42001. (10.1103/physrevd.110.042001)
- Abbott, R. et al. 2024. Search for gravitational-lensing signatures in the full third observing run of the LIGO–Virgo network. Astrophysical Journal 970(191) (10.3847/1538-4357/ad3e83)
- Abac, A. G. et al. 2024. Observation of gravitational waves from the coalescence of a 2.5–4.5 M ⊙ compact object and a neutron star. The Astrophysical Journal Letters 970(2), article number: L34. (10.3847/2041-8213/ad5beb)
- Abbott, R. et al. 2024. Search for gravitational-wave transients associated with magnetar bursts in Advanced LIGO and Advanced Virgo data from the third observing run. The Astrophysical Journal 966(1), article number: 137. (10.3847/1538-4357/ad27d3)
- Fletcher, C. et al. 2024. A joint Fermi-GBM and Swift-BAT analysis of Gravitational-wave candidates from the third Gravitational-wave Observing Run. The Astrophysical Journal 964(2), article number: 149. (10.3847/1538-4357/ad1eed)
- Sakai, Y. et al. 2024. Training process of unsupervised learning architecture for gravity spy dataset. Annalen der Physik 536(2), article number: 2200140. (10.1002/andp.202200140)
- Abbott, R. et al. 2023. Open Data from the Third Observing Run of LIGO, Virgo, KAGRA, and GEO. Astrophysical Journal Supplement 267(2), article number: 29. (10.3847/1538-4365/acdc9f)
- Abbott, R. et al. 2023. Constraints on the cosmic expansion history from GWTC–3. Astrophysical Journal 949(2), article number: 76. (10.3847/1538-4357/ac74bb)
- Abe, H. et al. 2023. Noise subtraction from KAGRA O3GK data using Independent Component Analysis. Classical and Quantum Gravity 40(8), article number: 85015. (10.1088/1361-6382/acc0cb)
- Akutsu, T. et al. 2023. Input optics systems of the KAGRA detector during O3GK. Progress of Theoretical and Experimental Physics 2023(2), article number: 023F01. (10.1093/ptep/ptac166)
- Abbott, R. et al. 2022. Model-based cross-correlation search for gravitational waves from the low-mass x-ray binary scorpius x-1 in ligo o3 data. Astrophysical Journal Letters 941(2), article number: L30. (10.3847/2041-8213/aca1b0)
- Fairhurst, S. et al. 2022. All-sky search for continuous gravitational waves from isolated neutron stars using Advanced LIGO and Advanced Virgo O3 data. Physical Review D 106(10) (10.1103/PhysRevD.106.102008)
- Abe, H. et al. 2022. Performance of the KAGRA detector during the first joint observation with GEO 600 (O3GK). Progress of Theoretical and Experimental Physics, article number: ptac093. (10.1093/ptep/ptac093)
- Abe, H. et al. 2022. The current status and future prospects of KAGRA, the large-scale cryogenic gravitational wave telescope built in the Kamioka underground. Galaxies 10(3), article number: 63. (10.3390/galaxies10030063)
- Sakai, Y. et al. 2022. Unsupervised learning architecture for classifying the transient noise of interferometric gravitational-wave detectors. Scientific Reports 12(1), article number: 9935. (10.1038/s41598-022-13329-4)
- Abbott, R. et al. 2022. Searches for gravitational waves from known pulsars at two harmonics in the second and third LIGO-Virgo observing runs. Astrophysical Journal 935(1), article number: 1. (10.3847/1538-4357/ac6acf)
- Abbott, R. et al. 2022. Search for gravitational waves associated with gamma-ray bursts detected by Fermi and Swift during the LIGO-Virgo Run O3b. Astrophysical Journal 928(2), article number: 186. (10.3847/1538-4357/ac532b)
- Abbott, R. et al. 2022. Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo. Astronomy & Astrophysics 659, article number: A84. (10.1051/0004-6361/202141452)
- Abbott, R. et al. 2022. Constraints on dark photon dark matter using data from LIGO's and Virgo's third observing run. Physical Review D 105(6), article number: 63030. (10.1103/PhysRevD.105.063030)
- Abbott, R. et al. 2021. All-sky search for short gravitational-wave bursts in the third Advanced LIGO and Advanced Virgo run. Physical Review D 104, article number: 122004. (10.1103/PhysRevD.104.122004)
- Akutsu, T. et al. 2021. Overview of KAGRA: Calibration, detector characterization, physical environmental monitors, and the geophysics interferometer. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A102. (10.1093/ptep/ptab018)
- Kawamura, S. et al. 2021. Current status of space gravitational wave antenna DECIGO and B-DECIGO. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A105. (10.1093/ptep/ptab019)
- Akutsu, T. et al. 2021. Overview of KAGRA: KAGRA science. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A103. (10.1093/ptep/ptaa120)
- Akutsu, T. et al. 2021. Overview of KAGRA: Detector design and construction history. Progress of Theoretical and Experimental Physics 2021(5), article number: 05A101. (10.1093/ptep/ptaa125)
- Akutsu, T. et al. 2021. Radiative cooling of the thermally isolated system in KAGRA gravitational wave telescope. Journal of Physics: Conference Series 1857(1), article number: 12002. (10.1088/1742-6596/1857/1/012002)
- Yamada, R. et al. 2020. Optimization of quantum noise by completing the square of multiple interferometer outputs in quantum locking for gravitational wave detectors. Physics Letters A 384(26), article number: 126626. (10.1016/j.physleta.2020.126626)
- Abbott, B. P. et al. 2020. Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA. Living Reviews in Relativity 23(1), article number: 3. (10.1007/s41114-020-00026-9)
- Zhu, Z. -. et al. 2020. Application of independent component analysis to the iKAGRA data. Progress of Theoretical and Experimental Physics 2020(5), article number: 053F01. (10.1093/ptep/ptaa056)
- Akutsu, T. et al. 2020. An arm length stabilization system for KAGRA and future gravitational-wave detectors. Classical and Quantum Gravity 37(3), article number: 35004. (10.1088/1361-6382/ab5c95)
- Yamamoto, K. et al. 2019. Design and experimental demonstration of a laser modulation system for future gravitational-wave detectors. Classical and Quantum Gravity 36(20), article number: 205009. (10.1088/1361-6382/ab4489)
- Akiyama, Y. et al. 2019. Vibration isolation system with a compact damping system for power recycling mirrors of KAGRA. Classical and Quantum Gravity 36(9), article number: 95015. (10.1088/1361-6382/ab0fcb)
- KAGRA collaboration, . and Kokeyama, K. 2019. KAGRA: 2.5 generation interferometric gravitational wave detector. Nature Astronomy 3(1), pp. 35-40. (10.1038/s41550-018-0658-y)
- Kokeyama, K. et al. 2018. Demonstration for a two-axis interferometric tilt sensor in KAGRA. Physics Letters A 382(29), pp. 1950-1955. (10.1016/j.physleta.2018.05.004)
- Akutsu, T. et al. 2018. Construction of KAGRA: an underground gravitational-wave observatory. Progress of Theoretical and Experimental Physics 2018(1), article number: 013F01. (10.1093/ptep/ptx180)
- Abbott, B. P. et al. 2016. GW150914: the advanced LIGO detectors in the era of first discoveries. Physical Review Letters 116(13), article number: 131103. (10.1103/PhysRevLett.116.131103)
- Abbott, B. P. et al. 2016. Astrophysical implications of the binary black hole merger GW150914. Astrophysical Journal Letters 818(2), article number: L22. (10.3847/2041-8205/818/2/L22)
- Abbott, B. P. et al. 2016. Observation of gravitational waves from a binary black hole merger. Physical Review Letters 116(6), article number: 61102. (10.1103/PhysRevLett.116.061102)
- Mueller, C. L. et al. 2016. The advanced LIGO input optics. Review of Scientific Instruments 87(1), article number: 14502. (10.1063/1.4936974)
- Evans, M. et al. 2015. Observation of Parametric Instability in Advanced LIGO. Physical Review Letters 114(16), article number: 161102. (10.1103/PhysRevLett.114.161102)
- Staley, A. et al. 2014. Achieving resonance in the advanced LIGO gravitational-wave interferometer. Classical and Quantum Gravity 31(24), article number: 245010. (10.1088/0264-9381/31/24/245010)
- Kokeyama, K., Izumi, K., Korth, W. Z., Smith-Lefebvre, N., Arai, K. and Adhikari, R. X. 2014. Residual amplitude modulation in interferometric gravitational wave detectors. Journal of the Optical Society of America A 31(1), pp. 81-88. (10.1364/JOSAA.31.000081)
- Lodhia, D., Brown, D., Brückner, F., Carbone, L., Fulda, P., Kokeyama, K. and Freise, A. 2013. Interferometer phase noise due to beam misalignment on diffraction gratings. Optics Express 21(24), pp. 29578-29591. (10.1364/OE.21.029578)
- Bond, C., Fulda, P., Carbone, L., Kokeyama, K. and Freise, A. 2011. Higher order Laguerre-Gauss mode degeneracy in realistic, high finesse cavities. Physical Review D - Particles, Fields, Gravitation and Cosmology 84(10), article number: 102002. (10.1103/PhysRevD.84.102002)
- Somiya, K., Kokeyama, K. and Nawrodt, R. 2010. Remarks on thermoelastic effects at low temperatures and quantum limits in displacement measurements. Physical Review D, Particles and fields 63(8), article number: 127101. (10.1103/PHYSREVD.82.127101)
- Fulda, P., Kokeyama, K., Chelkowski, S. and Freise, A. 2010. Experimental demonstration of higher-order Laguerre-Gauss mode interferometry. Physical Review D - Particles, Fields, Gravitation and Cosmology 82(1), article number: 12002. (10.1103/PhysRevD.82.012002)
- Kokeyama, K., Sato, S., Nishizawa, A., Kawamura, S., Chen, Y. and Sugamoto, A. 2009. Development of a displacement- and frequency-noise-free interferometer in a 3D configuration for gravitational wave detection. Physical Review Letters 103, article number: 171101. (10.1103/PhysRevLett.103.171101)
- Kokeyama, K., Somiya, K., Kawazoe, F., Sato, S., Kawamura, S. and Sugamoto, A. 2008. Development of a signal-extraction scheme for resonant sideband extraction. Classical and Quantum Gravity 25(23), article number: 235013. (10.1088/0264-9381/25/23/235013)
- Sato, S. et al. 2008. Demonstration of displacement-noise-free interferometry using bi-directional Mach-Zehnder interferometers. Classical and Quantum Gravity 25(11), article number: 114031. (10.1088/0264-9381/25/11/114031)
- Sato, S., Kawamura, S., Kokeyama, K., Kawazoe, F. and Somiya, K. 2007. Diagonalization of the length sensing matrix of a dual recycled laser interferometer gravitational wave antenna. Physical Review D - Particles, Fields, Gravitation and Cosmology 75(8), article number: 82004. (10.1103/PhysRevD.75.082004)
- Sato, S., Kokeyama, K., Ward, R. L., Kawamura, S., Chen, Y., Pai, A. and Somiya, K. 2007. Demonstration of displacement- and frequency-noise-free laser interferometry using bidirectional Mach-Zehnder Interferometers. Physical Review Letters 98(14), article number: 141101. (10.1103/PhysRevLett.98.141101)
- Chen, Y. et al. 2006. Interferometers for displacement-noise-free gravitational-wave detection. Physical Review Letters 97(15), article number: 151103. (10.1103/PhysRevLett.97.151103)
- Kokeyama, K., Sato, S., Kawazoe, F., Somiya, K., Fukushima, M., Kawamura, S. and Sugamoto, A. 2006. Downselect of the signal extraction scheme for LCGT. Journal of Physics: Conference Series 32, article number: 65. (10.1088/1742-6596/32/1/065)
- Kawazoe, F. et al. 2006. The experimental plan of the 4m resonant sideband extraction prototype for the LCGT. Journal of Physics: Conference Series 32, pp. 380-385., article number: 58. (10.1088/1742-6596/32/1/058)
- Sato, S., Kokeyama, K., Kawazoe, F., Somiya, K. and Kawamura, S. 2006. Diagonalizing sensing matrix of broadband RSE. Journal of Physics: Conference Series 32, pp. 470-475., article number: 72. (10.1088/1742-6596/32/1/072)
Conferences
- Fulda, P. et al. 2012. Review of the Laguerre-Gauss mode technology research program at Birmingham. Presented at: 9th Edoardo Amaldi Conference and Numerical Relativity - Data Analysis Meeting (Amaldi 9/NRDA 2011), Cardiff, Wales, 10-15 July 2011, Vol. 363. IOP Publishing: Conference Series pp. 12010., (10.1088/1742-6596/363/1/012010)
- Kokeyama, K. et al. 2008. The experimental plan of displacement- and frequency-noise free laser interferometer. Presented at: The Seventh Edoardo Amaldi Conference On Gravitational Waves (amaldi7), Sydney, Australia, 8-14 July 2007, Vol. 122. IOP Publishing: Conference Series, (10.1088/1742-6596/122/1/012022)
Research
My research interests fall within the field of detector science for gravitational wave astrophysics.
- Laser source at a wavelength of 2 um for the next generation of gravitational wave detectors
- Better tilt sensor for the interferometer mirrors
- New type of phase camera to measure optics birefringence
Teaching
Join my gravitational-wave classes and projects!
2021-22, 2022-23
- Experimental Gravitational-Wave Physics II (PXT902)
- Experimental Physics (PXT1150)
- Physics Project (PXT3315 and 3350)
- MSC Physics Project (PXT999)
2021-22
- Experimental Gravitational-Wave Physics II (PXT902)
Biography
Professional memberships
- KAGRA Scientific Congress Board
- LIGO Scientific Collaboration
- KAGRA Collaboration
Academic positions
- 2021-Present: Lecturer, Cardiff University, UK.
- 2017-2021: Assistant Professor, Institute for Cosmic Ray Research, The University of Tokyo, Japan
- 2015-2017: Project Assistant Professor, Institute for Cosmic Ray Research, The University of Tokyo, Japan
- 2011-2015: Postdoctoral researcher, Louisiana State University, US.
- 2009-2011: Postdoctoral researcher, University of Birmingham, UK.
Contact Details
KokeyamaK@cardiff.ac.uk
+44 29225 14051
Queen's Buildings, Floor 2, Room N/2.13, 5 The Parade, Newport Road, Cardiff, CF24 3AA
+44 29225 14051
Queen's Buildings, Floor 2, Room N/2.13, 5 The Parade, Newport Road, Cardiff, CF24 3AA
