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Relativity and Gravitation Group

Dr Toshiya Namikawa

Career

  • 2019 - Now : Senior Research Associate, DAMTP, University of Cambridge
  • 2018 - 2018: Assistant Researcher (termed Assistant Professor), National Taiwan Univeristy
  • 2014 - 2017: Postdoctoral Researcher (with JSPS fellowship for two years), KIPAC, Stanford University
  • 2013 - 2014: Postdoctoral Researcher, Yukawa Institute for Theoretical Physics, Kyoto University
  • 2010 - 2013: PhD Student, University of Tokyo
  • 2008 - 2010: Master Student, University of Tokyo

Research

Toshiya is a member of the Department of Applied Mathematics and Theoretical Physics, in the Relativity and Gravitation research group. He is working on data-driven cosmology, the intersection between theoretical and observational cosmology. His current interests include B-mode analysis, gravitational lensing of CMB, cosmic birefringence, reionization and non-Gaussianity. He is an active member of several CMB experiments. 

 

Selected Publications

  • T. Namikawa et al. (ACTPol Collaboration), "The Atacama Cosmology Telescope: Constraints on Cosmic Birefringence", Phys. Rev. D, 101, 10465, 2020, arXiv:2001.10465
  • T. Namikawa et al. (POLARBEAR and Subaru-HSC Collaborations), "Evidence for the Cross-correlation between Cosmic Microwave Background Polarization Lensing from POLARBEAR and Cosmic Shear from Subaru Hyper Suprime-Cam", Astrophys. J., 882, 12, 2019, arXiv:1904.02116
  • BICEP2/Keck Array Collaborations, "BICEP2 / Keck Array X: Improved Constraints on Inflationary Gravitational Waves using BICEP2/Keck Data up to the 2015 Season in Conjunction with WMAP/Planck", Phys. Rev. Lett., 121, 221301, 2018, arXiv:1810.05216
  • T. Namikawa, "CMB internal delensing with general optimal estimator for higher-order correlations", Phys. Rev. D, 95, 103514, 2017, arXiv:1703.00169
  • BICEP2/Keck Array Collaborations, "BICEP2 / Keck Array IX: New Bounds on Anisotropies of CMB Polarization Rotation and Implications for Axion-Like Particles and Primordial Magnetic Fields", Phys. Rev. D, 96, 102003, 2017, arXiv:1705.02523
  • BICEP2/Keck Array Collaborations, "BICEP2 / Keck Array VIII: Measurement of Gravitational Lensing from Large-Scale B-mode Polarization", Astrophys. J., 833, 228, 2016, arXiv:1606.01968
  • T. Namikawa, "CMB Lensing bispectrum from Nonlinear Growth of the Large Scale Structure", Phys. Rev. D Rapid Communications, 93, 121301, 2016, arXiv:1604.08578
  • T. Namikawa et al., "Anisotropies of gravitational-wave standard sirens as a new cosmological probe without redshift information", Phys. Rev. Lett., 116, 0121302, 2016, arXiv:1511.04638
  • T. Namikawa et al.. "Bias-Hardened CMB Lensing", Mon. Not. R. Astron. Soc., 431, 609, 2013, arXiv:1209.0091
  • T. Namikawa et al., "Full-sky lensing reconstruction of gradient and curl modes from CMB maps", J. Cosmol. Astropart. Phys., 01, 007, 2012, arXiv:1110.1718

Publications

Optical Characterization of the Keck Array and BICEP3 CMB Polarimeters from 2016 to 2019
TBICEPK Collaboration, TS Germaine, PAR Ade, Z Ahmed, M Amiri, D Barkats, RB Thakur, CA Bischoff, JJ Bock, H Boenish, E Bullock, V Buza, J Cheshire, J Connors, J Cornelison, M Crumrine, A Cukierman, M Dierickx, L Duband, S Fatigoni, JP Filippini, S Fliescher, JA Grayson, G Hall, M Halpern, S Harrison, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, J Kang, KS Karkare, E Karpel, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, K Lau, EM Leitch, KG Megerian, L Moncelsi, T Namikawa, CB Netterfield, HT Nguyen, R O'Brient, RWO IV, S Palladino, C Pryke, B Racine, CD Reintsema, S Richter, A Schillaci, R Schwarz, CD Sheehy, A Soliman, B Steinbach, RV Sudiwala, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umilta, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, E Yang, KW Yoon, E Young, C Yu, C Zhang
– Journal of Low Temperature Physics
(2020)
199,
824
(doi: 10.1007/s10909-020-02392-8)
The weak lensing bispectrum induced by gravity
D Munshi, T Namikawa, TD Kitching, JD McEwen, R Takahashi, FR Bouchet, A Taruya, B Bose
– Monthly Notices of the Royal Astronomical Society
(2020)
493,
3985
(doi: 10.1093/mnras/staa296)
Design and Performance of the First BICEP Array Receiver
A Schillaci, PAR Ade, Z Ahmed, M Amiri, D Barkats, RB Thakur, CA Bischoff, JJ Bock, H Boenish, E Bullock, V Buza, J Cheshire, J Connors, J Cornelison, M Crumrine, A Cukierman, M Dierickx, L Duband, S Fatigoni, JP Filippini, G Hall, M Halpern, S Harrison, S Henderson, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, J Kang, KS Karkare, E Karpel, S Kefeli, JM Kovac, CL Kuo, K Lau, KG Megerian, L Moncelsi, T Namikawa, HT Nguyen, R O’Brient, S Palladino, N Precup, T Prouve, C Pryke, B Racine, CD Reintsema, S Richter, BL Schmitt, R Schwarz, CD Sheehy, A Soliman, TS Germaine, B Steinbach, RV Sudiwala, KL Thompson, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, WLK Wu, E Yang, KW Yoon, E Young, C Yu, C Zhang
– Journal of Low Temperature Physics
(2020)
199,
976
(doi: 10.1007/s10909-020-02394-6)
Updated Design of the CMB Polarization Experiment Satellite LiteBIRD
H Sugai, PAR Ade, Y Akiba, D Alonso, K Arnold, J Aumont, J Austermann, C Baccigalupi, AJ Banday, R Banerji, RB Barreiro, S Basak, J Beall, S Beckman, M Bersanelli, J Borrill, F Boulanger, ML Brown, M Bucher, A Buzzelli, E Calabrese, FJ Casas, A Challinor, V Chan, Y Chinone, JF Cliche, F Columbro, A Cukierman, D Curtis, P Danto, P de Bernardis, T de Haan, M De Petris, C Dickinson, M Dobbs, T Dotani, L Duband, A Ducout, S Duff, A Duivenvoorden, JM Duval, K Ebisawa, T Elleflot, H Enokida, HK Eriksen, J Errard, T Essinger-Hileman, F Finelli, R Flauger, C Franceschet, U Fuskeland, K Ganga, JR Gao, R Génova-Santos, T Ghigna, A Gomez, ML Gradziel, J Grain, F Grupp, A Gruppuso, JE Gudmundsson, NW Halverson, P Hargrave, T Hasebe, M Hasegawa, M Hattori, M Hazumi, S Henrot-Versille, D Herranz, C Hill, G Hilton, Y Hirota, E Hivon, R Hlozek, DT Hoang, J Hubmayr, K Ichiki, T Iida, H Imada, K Ishimura, H Ishino, GC Jaehnig, M Jones, T Kaga, S Kashima, Y Kataoka, N Katayama, T Kawasaki, R Keskitalo, A Kibayashi, T Kikuchi, K Kimura, T Kisner, Y Kobayashi, N Kogiso, A Kogut, K Kohri, E Komatsu, K Komatsu, K Konishi
– Journal of Low Temperature Physics
(2020)
199,
1107
(doi: 10.1007/s10909-019-02329-w)
Receiver development for BICEP Array, a next-generation CMB polarimeter at the South Pole
L Moncelsi, PAR Ade, Z Ahmed, M Amiri, D Barkats, R Basu Thakur, CA Bischoff, JJ Bock, V Buza, JR Cheshire, J Connors, J Cornelison, M Crumrine, AJ Cukierman, EV Denison, M Dierickx, L Duband, M Eiben, S Fatigoni, JP Filippini, N Goeckner-Wald, D Goldfinger, JA Grayson, P Grimes, G Hall, M Halpern, SA Harrison, S Henderson, SR Hildebrandt, GC Hilton, J Hubmayr, H Hui, KD Irwin, JH Kang, KS Karkare, S Kefeli, JM Kovac, CL Kuo, K Lau, EM Leitch, KG Megerian, L Minutolo, Y Nakato, T Namikawa, HT Nguyen, R O'Brient, S Palladino, N Precup, T Prouve, C Pryke, B Racine, CD Reintsema, A Schillaci, BL Schmitt, A Soliman, T St. Germaine, B Steinbach, RV Sudiwala, KL Thompson, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, WLK Wu, E Yang, KW Yoon, E Young, C Yu, L Zeng, C Zhang, S Zhang
– Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy X
(2020)
11453,
41
(doi: 10.1117/12.2561995)
Polarization calibration of the BICEP3 CMB polarimeter at the South Pole
J Cornelison, PAR Ade, Z Ahmed, M Amiri, D Barkats, R Basu Thakur, C Bischoff, JJ Bock, H Boenish, E Bullock, V Buza, JR Cheshire, J Connors, M Crumrine, AJ Cukierman, EV Denison, M Dierickx, L Duband, M Eiben, S Fatigoni, JP Filippini, S Fliescher, N Goeckner-Wald, DC Goldfinger, JA Grayson, P Grimes, G Hall, G Halal, M Halpern, SA Harrison, S Henderson, S Hildebrandt, GC Hilton, J Hubmayr, H Hui, KD Irwin, J Kang, K Karkare, E Karpel, S Kefeli, SA Kernasovkiy, JM Kovac, CL Kuo, K Lau, E Leitch, KG Megerian, L Minutolo, L Moncelsi, Y Nakato, T Namikawa, HT Nguyen, R O'Brient, RW Ogburn, S Palladino, N Precup, T Prouve, C Pryke, B Racine, CD Reintsema, S Richter, A Schillaci, B Schmitt, R Schwarz, CD Sheehy, A Soliman, T St. Germaine, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umilta, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, E Yang, KW Yoon, E Young, C Yu, L Zeng, C Zhang, S Zhang
– Proceedings of SPIE - The International Society for Optical Engineering
(2020)
11453,
149
(doi: 10.1117/12.2562905)
Observing low elevation sky and the CMB Cold Spot with BICEP3 at the South Pole
JH Kang, PAR Ade, Z Ahmed, M Amiri, D Barkats, R Basu Thakur, CA Bischoff, JJ Bock, H Boenish, E Bullock, V Buza, JR Cheshire, J Connors, J Cornelison, M Crumrine, A Cukierman, E Denison, M Dierickx, L Duband, M Eiben, S Fatigoni, JP Filippini, S Fliescher, N Goeckner-Wald, D Goldfinger, JA Grayson, P Grimes, G Hall, M Halpern, SA Harrison, S Henderson, SR Hildebrandt, GC Hilton, J Hubmayr, H Hui, KD Irwin, KS Karkare, E Karpel, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, K Lau, EM Leitch, KG Megerian, L Minutolo, L Moncelsi, Y Nakato, T Namikawa, HT Nguyen, R Obrient, RW Ogburn, S Palladino, N Precup, T Prouve, C Pryke, B Racine, CD Reintsema, S Richter, A Schillaci, BL Schmitt, R Schwarz, CD Sheehy, A Soliman, T St Germaine, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umilta, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, E Yang, KW Yoon, E Young, C Yu, L Zeng, C Zhang, S Zhang
– Proceedings of SPIE - The International Society for Optical Engineering
(2020)
11453,
169
(doi: 10.1117/12.2562066)
Concept design of low frequency telescope for CMB B-mode polarization satellite LiteBIRD
Y Sekimoto, PAR Ade, A Adler, E Allys, K Arnold, D Auguste, J Aumont, R Aurlien, J Austermann, C Baccigalupi, AJ Banday, R Banerji, RB Barreiro, S Basak, J Beall, D Beck, S Beckman, J Bermejo, P De Bernardis, M Bersanelli, J Bonis, J Borrill, F Boulanger, S Bounissou, M Brilenkov, M Brown, M Bucher, E Calabrese, P Campeti, A Carones, FJ Casas, A Challinor, V Chan, K Cheung, Y Chinone, JF Cliche, L Colombo, F Columbro, J Cubas, A Cukierman, D Curtis, G D'Alessandro, N Dachlythra, M De Petris, C Dickinson, P Diego-Palazuelos, M Dobbs, T Dotani, L Duband, S Duff, JM Duval, K Ebisawa, T Elleflot, HK Eriksen, J Errard, T Essinger-Hileman, F Finelli, R Flauger, C Franceschet, U Fuskeland, M Galloway, K Ganga, JR Gao, R Genova-Santos, M Gerbino, M Gervasi, T Ghigna, E Gjerløw, ML Gradziel, J Grain, F Grupp, A Gruppuso, JE Gudmundsson, T De Haan, NW Halverson, P Hargrave, T Hasebe, M Hasegawa, M Hattori, M Hazumi, S Henrot-Versille, D Herman, D Herranz, CA Hill, G Hilton, Y Hirota, E Hivon, RA Hlozek, Y Hoshino, E De La Hoz, J Hubmayr, K Ichiki, T Iida, H Imada, K Ishimura, H Ishino, G Jaehnig, T Kaga, S Kashima, N Katayama
– Proceedings of SPIE - The International Society for Optical Engineering
(2020)
11453,
37
(doi: 10.1117/12.2561841)
LiteBIRD satellite: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization
M Hazumi, PAR Ade, A Adler, E Allys, K Arnold, D Auguste, J Aumont, R Aurlien, J Austermann, C Baccigalupi, AJ Banday, R Banjeri, RB Barreiro, S Basak, J Beall, D Beck, S Beckman, J Bermejo, P De Bernardis, M Bersanelli, J Bonis, J Borrill, F Boulanger, S Bounissou, M Brilenkov, M Brown, M Bucher, E Calabrese, P Campeti, A Carones, FJ Casas, A Challinor, V Chan, K Cheung, Y Chinone, JF Cliche, L Colombo, F Columbro, J Cubas, A Cukierman, D Curtis, G D'alessandro, N Dachlythra, M De Petris, C Dickinson, P Diego-Palazuelos, M Dobbs, T Dotani, L Duband, S Duff, JM Duval, K Ebisawa, T Elleflot, HK Eriksen, J Errard, T Essinger-Hileman, F Finelli, R Flauger, C Franceschet, U Fuskeland, M Galloway, K Ganga, JR Gao, R Genova-Santos, M Gerbino, M Gervasi, T Ghigna, E Gjerløw, ML Gradziel, J Grain, F Grupp, A Gruppuso, JE Gudmundsson, T De Haan, NW Halverson, P Hargrave, T Hasebe, M Hasegawa, M Hattori, S Henrot-Versillé, D Herman, D Herranz, CA Hill, G Hilton, Y Hirota, E Hivon, RA Hlozek, Y Hoshino, E De La Hoz, J Hubmayr, K Ichiki, T Iida, H Imada, K Ishimura, H Ishino, G Jaehnig, T Kaga, S Kashima, N Katayama, A Kato
– SPACE TELESCOPES AND INSTRUMENTATION 2020: OPTICAL, INFRARED, AND MILLIMETER WAVE
(2020)
11443,
114432f-114432f-20
(doi: 10.1117/12.2563050)
Overview of the Medium and High Frequency Telescopes of the LiteBIRD satellite mission
L Montier, B Mot, P De Bernardis, B Maffei, G Pisano, F Columbro, JE Gudmundsson, S Henrot-Versillé, L Lamagna, J Montgomery, T Prouvé, M Russell, G Savini, S Stever, KL Thompson, M Tsujimoto, C Tucker, B Westbrook, PAR Ade, A Adler, E Allys, K Arnold, D Auguste, J Aumont, R Aurlien, J Austermann, C Baccigalupi, AJ Banday, R Banerji, RB Barreiro, S Basak, J Beall, D Beck, S Beckman, J Bermejo, M Bersanelli, J Bonis, J Borrill, F Boulanger, S Bounissou, M Brilenkov, M Brown, M Bucher, E Calabrese, P Campeti, A Carones, FJ Casas, A Challinor, V Chan, K Cheung, Y Chinone, JF Cliche, L Colombo, J Cubas, A Cukierman, D Curtis, G D'alessandro, N Dachlythra, M De Petris, C Dickinson, P Diego-Palazuelos, M Dobbs, T Dotani, L Duband, S Duff, JM Duval, K Ebisawa, T Elleflot, HK Eriksen, J Errard, T Essinger-Hileman, F Finelli, R Flauger, C Franceschet, U Fuskeland, M Galloway, K Ganga, JR Gao, R Genova-Santos, M Gerbino, M Gervasi, T Ghigna, E Gjerløw, ML Gradziel, J Grain, F Grupp, A Gruppuso, T De Haan, NW Halverson, P Hargrave, T Hasebe, M Hasegawa, M Hattori, M Hazumi, D Herman, D Herranz, CA Hill, G Hilton, Y Hirota, E Hivon
– Space Telescopes and Instrumentation 2020: Optical, Infrared, and Millimeter Wave
(2020)
11443,
114432g-114432g-21
(doi: 10.1117/12.2562243)
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Research Group

Relativity and Gravitation

Email

tn334@damtp.cam.ac.uk

Room

B1.09

Telephone

01223 337843

Study at Cambridge

About the University

Research at Cambridge