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Department of Applied Mathematics and Theoretical Physics

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. D101, 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. D95, 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. D96, 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 Communications93, 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

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, T Kawasaki, R Keskitalo, T Kisner, Y Kobayashi, N Kogiso, A Kogut, K Kohri, E Komatsu, K Komatsu, K Konishi, N Krachmalnicoff, I Kreykenbohm, CL Kuo, A Kushino, L Lamagna, JV Lanen, M Lattanzi, AT Lee, C Leloup, F Levrier, E Linder, T Louis, G Luzzi, T Maciaszek, B Maffei, D Maino, M Maki, S Mandelli, E Martinez-Gonzalez, S Masi, T Matsumura, A Mennella, M Migliaccio, Y Minami, K Mitsuda, J Montgomery, L Montier, G Morgante, B Mot, Y Murata, JA Murphy, M Nagai, Y Nagano, T Nagasaki, R Nagata, S Nakamura, T Namikawa, P Natoli, S Nerval, T Nishibori, H Nishino, F Noviello, C O'Sullivan, H Ogawa, H Ogawa, S Oguri, H Ohsaki, IS Ohta, N Okada, N Okada, L Pagano, A Paiella, D Paoletti, G Patanchon, J Peloton, F Piacentini, G Pisano, G Polenta, D Poletti, T Prouvé, G Puglisi, D Rambaud, C Raum, S Realini, M Reinecke, M Remazeilles, A Ritacco, G Roudil, JA Rubino-Martin, M Russell, H Sakurai, Y Sakurai, M Sandri, M Sasaki, G Savini, D Scott, J Seibert, Y Sekimoto, B Sherwin, K Shinozaki, M Shiraishi, P Shirron, G Signorelli, G Smecher, S Stever, R Stompor, H Sugai, S Sugiyama, A Suzuki, J Suzuki, TL Svalheim, E Switzer, R Takaku, H Takakura, S Takakura, Y Takase, Y Takeda, A Tartari, E Taylor, Y Terao, H Thommesen, KL Thompson, B Thorne, T Toda, M Tomasi, M Tominaga, N Trappe, M Tristram, M Tsuji, M Tsujimoto, C Tucker, J Ullom, G Vermeulen, P Vielva, F Villa, M Vissers, N Vittorio, I Wehus, J Weller, B Westbrook, J Wilms, B Winter, EJ Wollack, NY Yamasaki, T Yoshida, J Yumoto, M Zannoni, A Zonca
– Proceedings of SPIE--the International Society for Optical Engineering
(2020)
11443,
114432f-114432f-20
Concept design of low frequency telescope for CMB B-mode polarization satellite LiteBIRD
Y Sekimoto, P Ade, A Adler, E Allys, K Arnold, D Auguste, J Aumont, R Aurlien, J Austermann, C Baccigalupi, A Banday, R Banerji, R 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, F Casas, A Challinor, V Chan, K Cheung, Y Chinone, J 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, J Duval, K Ebisawa, T Elleflot, H Eriksen, J Errard, T Essinger-Hileman, F Finelli, R Flauger, C Franceschet, U Fuskeland, M Galloway, K Ganga, J Gao, R Genova-Santos, M Gerbino, M Gervasi, T Ghigna, E Gjerløw, M Gradziel, J Grain, F Grupp, A Gruppuso, J Gudmundsson, T de Haan, N Halverson, P Hargrave, T Hasebe, M Hasegawa, M Hattori, M Hazumi, S Henrot-Versillé, D Herman, D Herranz, C Hill, G Hilton, Y Hirota, E hivon, R 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, T Kawasaki, R Keskitalo, T Kisner, Y Kobayashi, N Kogiso, A Kogut, K Kohri, E Komatsu, K Komatsu, K Konishi, N Krachmalnicoff, I Kreykenbohm, C-L Kuo, A Kushino, L Lamagna, J Lanen, M Lattanzi, A Lee, C Leloup, F Levrier, E Linder, T Louis, G Luzzi, T Maciaszek, B Maffei, D Maino, M Maki, S Mandelli, E Martinez-Gonzalez, S Masi, T Matsumura, A Mennella, M Migliaccio, Y Minanmi, K Mitsuda, J Montgomery, L Montier, G Morgante, B Mot, Y Murata, J Murphy, M Nagai, Y Nagano, T Nagasaki, R Nagata, S Nakamura, T Namikawa, P Natoli, S Nerval, T Nishibori, H Nishino, C O'Sullivan, H Ogawa, H Ogawa, S Oguri, H Osaki, I Ohta, N Okada, N Okada, L Pagano, A Paiella, D Paoletti, G Patanchon, J Peloton, F Piacentini, G Pisano, G Polenta, D Poletti, T Prouvé, G Puglisi, D Tambaud, C Raum, S Realini, M Reinecke, M Remazeilles, A Ritacco, G Roudil, J Rubino-Martin, M Russell, H Sakurai, Y Sakurai, M Sandri, M Sasaki, G Savini, D Scott, J Seibert, B Sherwin, K Shinozaki, M Shiraishi, P Shirron, G Signorelli, G Smecher, S Stever, R Stompor, H Sugai, S Sugiyama, A Suzuki, J Suzuki, T Svalheim, E Switzer, R Takaku, H Takakura, S Takakura, Y Takase, Y Takeda, A Tartari, E Taylor, Y Terao, H Thommesen, KL Thompson, B Thorne, T Toda, M Tomasi, M Tominaga, N Trappe, M Tristram, M Tsuji, M Tsujimoto, C Tucker, J Ullom, G Vermeulen, P Vielva, F Villa, M Vissers, N Vittorio, I Wehus, J Weller, B Westbrook, J Wilms, B Winter, E Wollack, NY Yamasaki, T Yoshida, J Yumoto, M Zannoni, A Zonca
– Proceedings of SPIE the International Society for Optical Engineering
(2020)
11453,
37
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, 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, T Kawasaki, R Keskitalo, T Kisner, Y Kobayashi, N Kogiso, A Kogut, K Kohri, E Komatsu, K Komatsu, K Konishi, N Krachmalnicoff, I Kreykenbohm, CL Kuo, A Kushino, JV Lanen, M Lattanzi, AT Lee, C Leloup, F Levrier, E Linder, T Louis, G Luzzi, T Maciaszek, D Maino, M Maki, S Mandelli, E Martinez-Gonzalez, S Masi, T Matsumura, A Mennella, M Migliaccio, Y Minami, K Mitsuda, G Morgante, Y Murata, JA Murphy, M Nagai, Y Nagano, T Nagasaki, R Nagata, S Nakamura, T Namikawa, P Natoli, S Nerval, T Nishibori, H Nishino, C O'Sullivan, H Ogawa, H Ogawa, S Oguri, H Ohsaki, IS Ohta, N Okada, N Okada, L Pagano, A Paiella, D Paoletti, G Patanchon, J Peloton, F Piacentini, G Polenta, D Poletti, G Puglisi, D Rambaud, C Raum, S Realini, M Reinecke, M Remazeilles, A Ritacco, G Roudil, JA Rubino-Martin, H Sakurai, Y Sakurai, M Sandri, M Sasaki, D Scott, J Seibert, Y Sekimoto, B Sherwin, K Shinozaki, M Shiraishi, P Shirron, G Signorelli, G Smecher, R Stompor, H Sugai, S Sugiyama, A Suzuki, J Suzuki, TL Svalheim, E Switzer, R Takaku, H Takakura, S Takakura, Y Takase, Y Takeda, A Tartari, E Taylor, Y Terao, H Thommesen, B Thorne, T Toda, M Tomasi, M Tominaga, N Trappe, M Tristram, M Tsuji, J Ullom, G Vermeulen, P Vielva, F Villa, M Vissers, N Vittorio, I Wehus, J Weller, J Wilms, B Winter, EJ Wollack, NY Yamasaki, T Yoshida, J Yumoto, M Zannoni, A Zonca
– Proceedings of SPIE the International Society for Optical Engineering
(2020)
11443,
114432g-114432g-21
Analysis of Temperature-To-Polarization Leakage in BICEP3 and Keck CMB Data from 2016 to 2018
T St Germaine, 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, AJ Cukierman, E Denison, M Dierickx, L Duband, M Eiben, S Fatigoni, J Filippini, S Fliescher, N Goeckner-Wald, D Goldfinger, JA Grayson, P Grimes, G Hall, M Halpern, SA Harrison, S Henderson, S Hildebrandt, GC Hilton, J Hubmayr, H Hui, KD Irwin, JH Kang, KS Karkare, E Karpel, S Kefeli, SA Kernasovskiy, JM Kovac, C-L Kuo, K Lau, EM 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, C Reintsema, S Richter, A Schillaci, B Schmitt, R Schwartz, CD Sheehy, A Soliman, B Steinbach, R Sudiwala, G Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umilta, AG Vieregg, A Wandui, AC Weber, D Wiebe, J Willmert, CL Wong, WLK Wu, H-I Yang, KW Yoon, E Young, C Yu, L Zeng, C Zhang, S Zhang
– Proceedings of SPIE the International Society for Optical Engineering
(2020)
11453,
171
Receiver development for BICEP Array, a next-generation CMB polarimeter at the South Pole
L Moncelsi, PA 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, E 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, S Hildebrandt, G Hilton, J Hubmayr, H Hui, KD Irwin, JH Kang, KS Karkare, S Kefeli, JM Kovac, C-L Kuo, K Lau, EM Leitch, KG Megerian, L Minutolo, Y Nakato, T Namikawa, HT Nguyen, RC O'brient, S Palladino, N Precup, T Prouve, C Pryke, B Racine, CD Reintsema, A Schillaci, B Schmitt, A Soliman, T St. Germaine, B Steinbach, R R.Sudiwala@astro.cf.ac.uk, KL Thompson, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, DV Wiebe, J Willmert, WLK Wu, H-IE Yang, KW Yoon, EY Young, C Yu, L Zeng, C Zhang, S Zhang
– Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy X
(2020)
11453,
41
Polarization calibration of the BICEP3 CMB polarimeter at the South Pole
J Cornelison, PARA Ade, Z Ahmed, M Amiri, D Barkats, R Basu Thakur, C Bischoff, J Bock, H Boenish, E Bullock, V Buza, JR Cheshire, J Connors, M Crumrine, AJ Cukierman, E Denison, M Dierickx, L Duband, M Eiben, S Fatigoni, J Filippini, S Fliescher, N Goeckner-Wald, DC Goldfinger, JA Grayson, P Grimes, G Hall, G Halal, M Halpern, S Harrison, S Henderson, S Hildebrandt, GC Hilton, J Hubmayr, H Hui, KD Irwin, JH Kang, K Karkare, E Karpel, S Kefeli, SA Kernasovkiy, JM Kovac, C-L Kuo, K Lau, E Leitch, KG Megerian, L Minutolo, L Moncelsi, Y Nakato, T Namikawa, H 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, R Sudiwala, G Teply, K Thompson, JE Tolan, C Tucker, AD Turner, C Umilita, AG Vieregg, A Wandui, A Weber, D Wiebe, J Willmert, CL Wong, K 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
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, AJ 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, S Hildebrandt, GC Hilton, J Hubmayr, H Hui, KD Irwin, KS Karkare, E Karpel, S Kefeli, SA Kernasovskiy, JM Kovac, C-L Kuo, K Lau, EM Leitch, KG Megerian, L Minutolo, L Moncelsi, Y Nakato, T Namikawa, HT Nguyen, R O'brient, RW Ogburn IV, 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, R Sudiwala, G Teply, KL Thompson, JE Tolan, C Tucker, AD Turner, C Umiltà, AG Vieregg, A Wandui, AC Weber, D Wiebe, J Willmert, CL Wong, WLK Wu, H-I 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
The Atacama Cosmology Telescope: A CMB lensing mass map over 2100 square degrees of sky and its cross-correlation with BOSS-CMASS galaxies
O Darwish, MS Madhavacheril, BD Sherwin, S Aiola, N Battaglia, JA Beall, DT Becker, JR Bond, E Calabrese, SK Choi, MJ Devlin, J Dunkley, R Dünner, S Ferraro, AE Fox, PA Gallardo, Y Guan, M Halpern, D Han, M Hasselfield, JC Hill, GC Hilton, M Hilton, AD Hincks, S-P Patty Ho, J Hubmayr, JP Hughes, BJ Koopman, A Kosowsky, J Van Lanen, T Louis, M Lungu, A MacInnis, L Maurin, J McMahon, K Moodley, S Naess, T Namikawa, F Nati, L Newburgh, JP Nibarger, MD Niemack, LA Page, B Partridge, FJ Qu, N Robertson, A Schillaci, B Schmitt, N Sehgal, C Sifón, DN Spergel, S Staggs, E Storer, A van Engelen, EJ Wollack
– Monthly Notices of the Royal Astronomical Society
(2020)
500,
2250
The Atacama Cosmology Telescope: Weighing Distant Clusters with the Most Ancient Light
MS Madhavacheril, C Sifón, N Battaglia, S Aiola, S Amodeo, JE Austermann, JA Beall, DT Becker, JR Bond, E Calabrese, SK Choi, EV Denison, MJ Devlin, SR Dicker, SM Duff, AJ Duivenvoorden, J Dunkley, R Dünner, S Ferraro, PA Gallardo, Y Guan, D Han, JC Hill, GC Hilton, M Hilton, J Hubmayr, KM Huffenberger, JP Hughes, BJ Koopman, A Kosowsky, J Van Lanen, E Lee, T Louis, A MacInnis, J McMahon, K Moodley, S Naess, T Namikawa, F Nati, L Newburgh, MD Niemack, LA Page, B Partridge, FJ Qu, NC Robertson, M Salatino, E Schaan, A Schillaci, BL Schmitt, N Sehgal, BD Sherwin, SM Simon, DN Spergel, S Staggs, ER Storer, JN Ullom, LR Vale, A van Engelen, EM Vavagiakis, EJ Wollack, Z Xu
– Astrophysical Journal Letters
(2020)
903,
l13
Weak lensing skew-spectrum
D Munshi, T Namikawa, TD Kitching, JD McEwen, FR Bouchet
– Monthly Notices of the Royal Astronomical Society
(2020)
498,
6057
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Research Group

Relativity and Gravitation

Room

B1.09

Telephone

01223 337843