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
Constraining ultralight ALP dark matter in light of cosmic birefringence
– Physical Review D
(2024)
110,
103525
(doi: 10.1103/physrevd.110.103525)
Efficient estimation of rotation-induced bias to reconstructed CMB lensing power spectrum
– Physical Review D
(2024)
110,
103507
(doi: 10.1103/physrevd.110.103507)
The Simons Observatory: Combining cross-spectral foreground cleaning with multitracer B-mode delensing for improved constraints on inflation
– Physical Review D
(2024)
110,
043532
(doi: 10.1103/physrevd.110.043532)
Efficient estimation of rotation-induced bias to reconstructed CMB
lensing power spectrum
(2024)
Constraining Ultralight ALP Dark Matter in Light of Cosmic Birefringence
(2024)
LiteBIRD science goals and forecasts: primordial magnetic fields
– Journal of Cosmology and Astroparticle Physics
(2024)
2024,
086
Systematic Effects on Lensing Reconstruction from a Patchwork of CMB Polarization Maps
– Progress of Theoretical and Experimental Physics
(2024)
2024,
083e01
(doi: 10.1093/ptep/ptae117)
The Atacama Cosmology Telescope: reionization kSZ trispectrum methodology and limits
– Monthly Notices of the Royal Astronomical Society
(2024)
532,
4247
(doi: 10.1093/mnras/stae1746)
Exact CMB B-mode power spectrum from anisotropic cosmic birefringence
– Physical Review D
(2024)
109,
123521
(doi: 10.1103/physrevd.109.123521)
Impact of beam far side-lobe knowledge in the presence of foregrounds for LiteBIRD
– Journal of Cosmology and Astroparticle Physics
(2024)
2024,
011
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