Professional Education


  • Master of Science, Science University Of Tokyo (2010)
  • Bachelor of Science, Kyoto University (2008)
  • Doctor of Philosophy, Science University Of Tokyo (2013)

Stanford Advisors


All Publications


  • Testing parity-violating physics from cosmic rotation power reconstruction PHYSICAL REVIEW D Namikawa, T. 2017; 95 (4)
  • BICEP2/KECK ARRAY VIII: MEASUREMENT OF GRAVITATIONAL LENSING FROM LARGE-SCALE B-MODE POLARIZATION ASTROPHYSICAL JOURNAL Ade, P. A., Ahmed, Z., Aikin, R. W., Alexander, K. D., Barkats, D., Benton, S. J., BISCHOFF, C. A., Bock, J. J., Bowens-Rubin, R., Brevik, J. A., Buder, I., Bullock, E., Buza, V., Connors, J., Crill, B. P., Duband, L., Dyorkin, C., Filippini, J. P., Fliescher, S., GRAYSON, J., Halpern, M., Harrison, S., Hildebrandt, S. R., Hilton, G. C., Hui, H., Irwin, K. D., Kang, J., Karkare, K. S., Karpel, E., Kaufman, J. P., Keating, B. G., Kefeli, S., Kernasoyskiy, S. A., Kovac, J. M., Kuo, C. L., Leitch, E. M., Lueker, M., Megerian, K. G., Namikawa, T., Netterfield, C. B., Nguyen, H. T., O'Brient, R., Ogburn, R. W., Orlando, A., Pryke, C., Richter, S., Schwarz, R., Sheehy, C. D., Staniszewski, Z. K., Steinbach, B., Sudiwala, R. V., Teply, G. P., Thompson, K. L., Tolan, J. E., Tucker, C., Turner, A. D., Vieregg, A. G., Weber, A. C., Wiebe, D. V., WILLMERT, J., Wong, C. L., Wu, W. L., Yoon, K. W. 2016; 833 (2)
  • Cosmology with the Square Kilometre Array by SKA-Japan PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN Yamauchi, D., Ichiki, K., Kohri, K., Namikawa, T., Oyama, Y., Sekiguchi, T., Shimabukuro, H., Takahashi, K., Takahashi, T., Yokoyama, S., Yoshikawa, K. 2016; 68 (6)
  • Testing statistics of the CMB B-mode polarization toward unambiguously establishing quantum fluctuation of the vacuum PHYSICAL REVIEW D Shiraishi, M., Hikage, C., Namba, R., Namikawa, T., Hazumi, M. 2016; 94 (4)
  • LiteBIRD: Mission Overview and Focal Plane Layout JOURNAL OF LOW TEMPERATURE PHYSICS Matsumura, T., Akiba, Y., Arnold, K., Borrill, J., Chendra, R., Chinone, Y., CUKIERMAN, A., De Haan, T., Dobbs, M., Dominjon, A., Elleflot, T., Errard, J., Fujino, T., Fuke, H., Goeckner-Wald, N., HALVERSON, N., Harvey, P., Hasegawa, M., Hattori, K., Hattori, M., Hazumi, M., Hill, C., Hilton, G., Holzapfel, W., Hori, Y., Hubmayr, J., Ichiki, K., Inatani, J., Inoue, M., Inoue, Y., Irie, F., Irwin, K., Ishino, H., Ishitsuka, H., Jeong, O., Karatsu, K., Kashima, S., Katayama, N., Kawano, I., Keating, B., Kibayashi, A., Kibe, Y., Kida, Y., Kimura, K., Kimura, N., Kohri, K., Komatsu, E., Kuo, C. L., Kuromiya, S., Kusaka, A., Lee, A., Linder, E., Matsuhara, H., Matsuoka, S., Matsuura, S., Mima, S., Mitsuda, K., Mizukami, K., Morii, H., Morishima, T., Nagai, M., Nagasaki, T., Nagata, R., Nakajima, M., Nakamura, S., Namikawa, T., Naruse, M., Natsume, K., Nishibori, T., Nishijo, K., Nishino, H., NITTA, T., Noda, A., Noguchi, T., Ogawa, H., Oguri, S., Ohta, I. S., Otani, C., Okada, N., Okamoto, A., Okamoto, A., Okamura, T., Rebeiz, G., Richards, P., Sakai, S., Sato, N., Sato, Y., Segawa, Y., Sekiguchi, S., Sekimoto, Y., Sekine, M., Seljak, U., Sherwin, B., Shinozaki, K., Shu, S., Stompor, R., Sugai, H., Sugita, H., Suzuki, T., Suzuki, A., Tajima, O., Takada, S., Takakura, S., Takano, K., Takei, Y., Tomaru, T., Tomita, N., Turin, P., Utsunomiya, S., Uzawa, Y., Wada, T., Watanabe, H., WESTBROOK, B., Whitehorn, N., Yamada, Y., Yamasaki, N., Yamashita, T., Yoshida, M., Yoshida, T., Yotsumoto, Y. 2016; 184 (3-4): 824-831
  • Detecting black-hole binary clustering via the second-generation gravitational-wave detectors PHYSICAL REVIEW D Namikawa, T., Nishizawa, A., Taruya, A. 2016; 94 (2)
  • BICEP2/KECK ARRAY. VII. MATRIX BASED E/B SEPARATION APPLIED TO BICEP2 AND THE KECK ARRAY ASTROPHYSICAL JOURNAL Ade, P. A., Ahmed, Z., Aikin, R. W., Alexander, K. D., Barkats, D., Benton, S. J., BISCHOFF, C. A., Bock, J. J., Bowens-Rubin, R., Brevik, J. A., Buder, I., Bullock, E., Buza, V., Connors, J., Crill, B. P., Duband, L., Dvorkin, C., Filippini, J. P., Fliescher, S., GRAYSON, J., Halpern, M., Harrison, S., Hildebrandt, S. R., Hilton, G. C., Hui, H., Irwin, K. D., Kang, J., Karkare, K. S., Karpel, E., Kaufman, J. P., Keating, B. G., Kefeli, S., Kernasovskiy, S. A., Kovac, J. M., Kuo, C. L., Leitch, E. M., Lueker, M., Megerian, K. G., Namikawa, T., Netterfield, C. B., Nguyen, H. T., O'Brient, R., Ogburn, R. W., Orlando, A., Pryke, C., Richter, S., Schwarz, R., Sheehy, C. D., Staniszewski, Z. K., Steinbach, B., Sudiwala, R. V., Teply, G. P., Thompson, K. L., Tolan, J. E., Tucker, C., Turner, A. D., Vieregg, A. G., Weber, A. C., Wiebe, D. V., WILLMERT, J., Wong, C. L., Wu, W. L., Yoon, K. W. 2016; 825 (1)
  • CMB lensing bispectrum from nonlinear growth of the large scale structure PHYSICAL REVIEW D Namikawa, T. 2016; 93 (12)
  • Constraining higher-order parameters for primordial non-Gaussianities from power spectra and bispectra of imaging surveys PHYSICAL REVIEW D Hashimoto, I., Taruya, A., Matsubara, T., Namikawa, T., Yokoyama, S. 2016; 93 (10)
  • Anisotropies of Gravitational-Wave Standard Sirens as a New Cosmological Probe without Redshift Information. Physical review letters Namikawa, T., Nishizawa, A., Taruya, A. 2016; 116 (12): 121302-?

    Abstract

    Gravitational waves (GWs) from compact binary stars at cosmological distances are promising and powerful cosmological probes, referred to as the GW standard sirens. With future GW detectors, we will be able to precisely measure source luminosity distances out to a redshift z∼5. To extract cosmological information, previously proposed cosmological studies using the GW standard sirens rely on source redshift information obtained through an extensive electromagnetic follow-up campaign. However, the redshift identification is typically time consuming and rather challenging. Here, we propose a novel method for cosmology with the GW standard sirens free from the redshift measurements. Utilizing the anisotropies of the number density and luminosity distances of compact binaries originated from the large-scale structure, we show that, once GW observations will be well established in the future, (i) these anisotropies can be measured even at very high redshifts (z≥2), where the identification of the electromagnetic counterpart is difficult, (ii) the expected constraints on the primordial non-Gaussianity with the Einstein Telescope would be comparable to or even better than the other large-scale structure probes at the same epoch, and (iii) the cross-correlation with other cosmological observations is found to have high-statistical significance, providing additional cosmological information at very high redshifts.

    View details for DOI 10.1103/PhysRevLett.116.121302

    View details for PubMedID 27058068

  • Anisotropies of Gravitational-Wave Standard Sirens as a New Cosmological Probe without Redshift Information PHYSICAL REVIEW LETTERS Namikawa, T., Nishizawa, A., Taruya, A. 2016; 116 (12)
  • Delensing cosmic microwave background B modes with the Square Kilometre Array Radio Continuum Survey PHYSICAL REVIEW D Namikawa, T., Yamauchi, D., Sherwin, B., Nagata, R. 2016; 93 (4)
  • Non-Gaussian structure of B-mode polarization after delensing JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS Namikawa, T., Nagata, R. 2015
  • Future detectability of gravitational-wave induced lensing from high-sensitivity CMB experiments PHYSICAL REVIEW D Namikawa, T., Yamauchi, D., Taruya, A. 2015; 91 (4)