KIYOSHI MASUI, Associate Professor of Physics
Photo credit: Spencer Fu

Assistant Professor of Physics


PHONE: (617) 452-4647

OFFICE: Ronald McNair Building, 37-664d



Area of Physics:

Astrophysics - Cosmology

Research Interests

Professor Masui works to understand fundamental physics and the evolution of the Universe through observations of the large-scale structure - the distribution of matter on scales much larger than galaxies. Focussing on theory and data analysis, he works principally with radio wavelength surveys to develop new observational probes such as hydrogen intensity mapping and fast radio bursts (FRBs).

Hydrogen Intensity Mapping is a method for rapidly surveying the large-scale structure in three dimensions using the 21-cm radio line from hydrogen’s hyperfine transition. Masui has shown that the technique will ultimately permit precise measurements of properties of the early and late Universe and enable sensitive searches for primordial gravitational waves. To this end, he is working with a new generation of rapid-survey digital radio telescopes that have no moving parts are rely on signal processing software running on large compute clusters to focus and steer. An example is the Canadian Hydrogen Intensity Mapping Experiment (CHIME), of which he is a core science team member.

Fast radio bursts are brief and energetic flashes of radio light of unknown astronomical origin. Masui led the team that discovered an FRB with the Green Bank Telescope and proved that its source resides far outside our Galaxy. He has also shown that surveys of thousands of bursts can be used to study large-scale structure and is part of an effort to add new digital instrumentation to CHIME to perform such a survey.

Biographical Sketch

Professor Masui studied engineering physics at Queen’s University in Canada and did his undergraduate thesis in experimental astroparticle physics working with Arthur B. McDonald. He received his PhD in physics in 2013 in the Canadian Institute for Theoretical Astrophysics (CITA) at the University of Toronto. For his graduate work he led one of the first radio surveys to use hydrogen to map large-scale structure beyond the local universe. He then moved to the University of British Columbia as a Canadian Institute for Advanced Research Global Scholar and subsequently a CITA National Fellow. He joined the MIT Department of Physics as an Assistant Professor in 2018.

Selected Publications

  • K. W. Masui, U.-L. Pen, and N. Turok, “Two- and Three-Dimensional Probes of Parity in Primordial Gravity Waves”, Phys. Rev. Lett. 118, 221301 (2017), arXiv:1702.06552.
  • K. Masui, H.-H. Lin, J. Sievers, et al., “Dense magnetized plasma associated with a fast radio burst”, Nature 528, 523 (2015), arXiv:1512.00529.
  • K. W. Masui and K. Sigurdson, “Dispersion Distance and the Matter Distribution of the Universe in Dispersion Space”, Phys. Rev. Lett. 115, 121301 (2015), arXiv:1506.01704.
  • E. R. Switzer, K. W. Masui, K. Bandura, et al., “Determination of z ∼ 0.8 neutral hydrogen fluctuations using the 21 cm intensity mapping autocorrelation”, Mon. Not. R. Astron. Soc. 434, L46 (2013), arXiv:1304.3712.
  • K. W. Masui, E. R. Switzer, N. Banavar, et al., “Measurement of 21 cm Brightness Fluctuations at z ∼ 0.8 in Cross-correlation”, Astrophys. J. Lett. 763, L20 (2013), arXiv:1208.0331.
  • K. W. Masui and U.-L. Pen, “Primordial Gravity Wave Fossils and Their Use in Testing Inflation”, Phys. Rev. Lett. 105, 161302 (2010), arXiv:1006.4181.

Last updated on July 15, 2020 4:22 PM