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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

2017 upgrade and performance of BICEP3: A 95GHz refracting telescope for degree-scale CMB polarization
JH Kang, PAR Ade, Z Ahmed, RW Aikin, KD Alexander, D Barkats, SJ Benton, CA Bischoff, JJ Bock, H Boenish, R Bowens-Rubin, JA Brevik, I Buder, E Bullock, V Buza, J Connors, J Cornelison, BP Crill, M Crumrine, M Dierickx, L Duband, C Dvorkin, JP Filippini, S Fliescher, JA Grayson, G Hall, M Halpern, S Harrison, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, KS Karkare, E Karpel, JP Kaufman, BG Keating, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, NA Larsen, K Lau, EM Leitch, M Lueker, KG Megerian, L Moncelsi, T Namikawa, B Netterfield, HT Nguyen, R O'Brient, RW Ogburn, S Palladino, C Pryke, B Racine, S Richter, A Schillaci, R Schwarz, CD Sheehy, A Soliman, T St Germaine, ZK Staniszewski, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, H Yang, KW Yoon, C Zhang
– Proceedings of SPIE - The International Society for Optical Engineering
(2018)
10708,
107082n
(doi: 10.1117/12.2313854)
BICEP Array cryostat and mount design
M Crumrine, PAR Ade, Z Ahmed, RW Aikin, KD Alexander, D Barkats, SJ Benton, CA Bischoff, JJ Bock, R Bowens-Rubin, JA Brevik, I Buder, E Bullock, V Buza, J Connors, J Cornelison, BP Crill, M Dierickx, L Duband, C Dvorkin, JP Filippini, S Fliescher, JA Grayson, G Hall, M Halpern, SA Harrison, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, JH Kang, KS Karkare, E Karpel, JP Kaufman, BG Keating, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, NA Larsen, K Lau, EM Leitch, MV Lueker, KG Megerian, L Moncelsi, T Namikawa, CB Netterfield, HT Nguyen, R O'Brient, RW Ogburn, S Palladino, C Pryke, B Racine, S Richter, R Schwarz, A Schillaci, CD Sheehy, A Soliman, T St Germaine, ZK Staniszewski, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, CE Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, E Yang, KW Yoon, C Zhang
– Proceedings of SPIE - The International Society for Optical Engineering
(2018)
10708,
107082d
(doi: 10.1117/12.2312829)
Ultra-thin large-aperture vacuum windows for millimeter wavelengths receivers
D Barkats, MI Dierickx, JM Kovac, C Pentacoff, PAR Ade, Z Ahmed, RW Aikin, KD Alexander, SJ Benton, CA Bischoff, JJ Bock, R Bowens-Rubin, JA Brevik, I Buder, E Bullock, V Buza, J Connors, J Cornelison, BP Crill, M Crumrine, L Duband, C Dvorkin, JP Filippini, S Fliescher, JA Grayson, G Hall, M Halpern, SA Harrison, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, J Kang, KS Karkare, E Karpel, JP Kaufman, BG Keating, S Kefeli, SA Kernasovskiy, CL Kuo, K Lau, NA Larsen, EM Leitch, M Lueker, KG Megerian, L Moncelsi, T Namikawa, HT Nguyen, R O'Brient, RW Ogburn, S Palladino, C Pryke, B Racine, S Richter, R Schwarz, A Schillaci, CD Sheehy, A Soliman, T St Germaine, ZK Staniszewski, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, H Yang, KW Yoon, C Zhang
– Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX
(2018)
10708,
90
(doi: 10.1117/12.2312585)
BICEP Array: A multi-frequency degree-scale CMB polarimeter
H Hui, PAR Ade, Z Ahmed, RW Aikin, KD Alexander, D Barkats, SJ Benton, CA Bischoff, JJ Bock, R Bowens-Rubin, JA Brevik, I Buder, E Bullock, V Buza, J Connors, J Cornelison, BP Crill, M Crumrine, M Dierickx, L Duband, C Dvorkin, JP Filippini, S Fliescher, J Grayson, G Hall, M Halpern, S Harrison, SR Hildebrandt, GC Hilton, KD Irwin, J Kang, KS Karkare, E Karpel, JP Kaufman, BG Keating, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, K Lau, NA Larsen, EM Leitch, M Lueker, KG Megerian, L Moncelsi, T Namikawa, CB Netterfield, HT Nguyen, R O'Brient, RW Ogburn, S Palladino, C Pryke, B Racine, S Richter, R Schwarz, A Schillaci, CD Sheehy, A Soliman, T St Germaine, ZK Staniszewski, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, E Yang, KW Yoon, C Zhang
– Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX
(2018)
10708,
49
(doi: 10.1117/12.2311725)
Design and performance of wide-band corrugated walls for the BICEP Array detector modules at 30/40 GHz
A Soliman, PAR Ade, Z Ahmed, RW Aikin, KD Alexander, D Barkats, SJ Benton, CA Bischoff, JJ Bock, R Bowens-Rubin, JA Brevik, I Buder, E Bullock, V Buza, J Connors, J Cornelison, BP Crill, M Crumrine, M Dierickx, L Duband, C Dvorkin, JP Filippini, S Fliescher, JA Grayson, G Hall, M Halpern, S Harrison, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, JH Kang, KS Karkare, E Karpel, JP Kaufman, BG Keating, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, K Lau, NA Larsen, EM Leitch, M Lueker, KG Megerian, L Moncelsi, T Namikawa, CB Netterfield, HT Nguyen, RO Brient, RW Ogburn, S Palladino, C Pryke, B Racine, S Richter, R Schwarz, A Schillaci, CD Sheehy, T St Germaine, ZK Staniszewski, B Steinbach, R Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umiltà, J Van Zyl, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, E Yang, KW Yoon, C Zhang
– Proceedings of SPIE - The International Society for Optical Engineering
(2018)
10708,
86
(doi: 10.1117/12.2312942)
Full-sky Gravitational Lensing Simulation for Large-area Galaxy Surveys and Cosmic Microwave Background Experiments
R Takahashi, T Hamana, M Shirasaki, T Namikawa, T Nishimichi, K Osato, K Shiroyama
– The Astrophysical Journal
(2017)
850,
24
(doi: 10.3847/1538-4357/aa943d)
BICEP2 / Keck Array IX: New bounds on anisotropies of CMB polarization rotation and implications for axionlike particles and primordial magnetic fields
PAR Ade, Z Ahmed, RW Aikin, KD Alexander, D Barkats, SJ Benton, CA Bischoff, JJ Bock, R Bowens-Rubin, JA Brevik, I Buder, E Bullock, V Buza, J Connors, BP Crill, L Duband, C Dvorkin, JP Filippini, S Fliescher, TS Germaine, T Ghosh, J Grayson, S Harrison, SR Hildebrandt, GC Hilton, H Hui, KD Irwin, J Kang, KS Karkare, E Karpel, JP Kaufman, BG Keating, S Kefeli, SA Kernasovskiy, JM Kovac, CL Kuo, N Larson, EM Leitch, KG Megerian, L Moncelsi, T Namikawa, CB Netterfield, HT Nguyen, R O'Brient, RW Ogburn, C Pryke, S Richter, A Schillaci, R Schwarz, CD Sheehy, ZK Staniszewski, B Steinbach, RV Sudiwala, GP Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, AG Vieregg, AC Weber, DV Wiebe, J Willmert, CL Wong, WLK Wu, KW Yoon
– Physical Review D
(2017)
96,
102003
(doi: 10.1103/PhysRevD.96.102003)
Geometry and growth contributions to cosmic shear observables
JMZ Matilla, Z Haiman, A Petri, T Namikawa
– Physical Review D
(2017)
96,
023513
(doi: 10.1103/physrevd.96.023513)
CMB internal delensing with general optimal estimator for higher-order correlations
T Namikawa
– Physical Review D
(2017)
95,
103514
(doi: 10.1103/physrevd.95.103514)
Testing parity-violating physics from cosmic rotation power reconstruction
T Namikawa
– Physical Review D
(2017)
95,
043523
(doi: 10.1103/physrevd.95.043523)
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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