Junwu Parham picture

Perimeter Institute for Theoretical Physics

Research Faculty

Areas of research: Cosmology Particle Physics

(519) 569-7600 x7581

Teaching Affiliations
If you are interested in pursuing a MSc degree, please apply to the Perimeter Scholars International (PSI) masters program. Perimeter Institute is committed to diversity within its community and I welcome applications from underrepresented groups.
Research Interests

I am primarily interested in understanding what lies beyond the Standard Model of particle physics. I am interested in pursuing novel, low-energy experiments for weakly-coupled particles that may make use of small-scale experimental techniques. The main goal is to device sensitive experiments with current technology and understand how and how much it can be improved in the future. I am interested in understanding the dynamics and observational consequences of collective phenomenon in the dark matter fluid, which leads to, for example, formation of topological defects. I am also interested in designing new searches based on astrophysical and cosmological measurements, including aLIGO, CMB, LSS and 21cm cosmology. These searches allow us to look for new physics motivated by string theory, including axions, cosmic strings, and new vacua in the landscape. 

Positions Held
  • 5 Year Senior Postdoctoral Researcher, Perimeter Institute for Theoretical Physics, 2020-2022
  • Postdoctoral Researcher, Perimeter Institute for Theoretical Physics, 2017-2020
  • PhD Student, Stanford Institute of Theoretical Physics, Stanford University, 2012-2017
Recent Publications
  • Yin, W. W., ???., Dai, L., ??., Huang, J., ???., . . . Ferraro, S. (2025). New Probe of Cosmic Birefringence Using Galaxy Polarization and Shapes. Physical Review Letters, 134(16), 161001. doi:10.1103/physrevlett.134.161001
  • Mirasola, L., Mondino, C., Amicucci, F., Siemonsen, N., Palomba, C., D’Antonio, S., . . . East, W. E. (2025). Search for continuous gravitational wave signals from luminous dark photon superradiance clouds with LVK O3 observations. Physical Review D, 111(8), 084032. doi:10.1103/physrevd.111.084032
  • Fedderke, M. A., Huang, J., & Siemonsen, N. (2025). Periodic Cosmic String Formation and Dynamics. arxiv:2503.03116v1
  • Goldstein, S., McCarthy, F., Mondino, C., Hill, J. C., Huang, J., & Johnson, M. C. (2025). Constraints on Axions from Patchy Screening of the Cosmic Microwave Background. Physical Review Letters, 134(8), 081001. doi:10.1103/physrevlett.134.081001
  • Mirasola, L., Mondino, C., Amicucci, F., Siemonsen, N., Palomba, C., D'Antonio, S., . . . East, W. E. (2025). Search for continuous gravitational wave signals from luminous dark photon superradiance clouds with LVK O3 observations. doi:10.48550/arxiv.2501.02052
  • Brzeminski, D., Hook, A., Huang, J., & Ristow, C. (n.d.). Searching for string bosenovas with gravitational wave detectors. Journal of High Energy Physics, 2025(1), 7. doi:10.1007/jhep01(2025)007
  • Kumamoto, M., Huang, J., Drischler, C., Baryakhtar, M., & Reddy, S. (2024). Pi in the Sky: Neutron Stars with Exceptionally Light QCD Axions. arxiv:2410.21590v2
  • McCarthy, F., Pîrvu, D., Hill, J. C., Huang, J., Johnson, M. C., & Rogers, K. K. (2024). Dark Photon Limits from Patchy Dark Screening of the Cosmic Microwave Background. Physical Review Letters, 133(14), 141003. doi:10.1103/physrevlett.133.141003
  • Mondino, C., Pîrvu, D., Huang, J., & Johnson, M. C. (2024). Axion-induced patchy screening of the Cosmic Microwave Background. Journal of Cosmology and Astroparticle Physics, 2024(10), 107. doi:10.1088/1475-7516/2024/10/107
  • Goldstein, S., McCarthy, F., Mondino, C., Hill, J. C., Huang, J., & Johnson, M. C. (2024). Constraints on axions from patchy screening of the cosmic microwave background. doi:10.48550/arxiv.2409.10514
  • Brzeminski, D., Hook, A., Huang, J., & Ristow, C. (2024). Searching for String Bosenovas with Gravitational Wave Detectors. doi:10.48550/arxiv.2407.18991
  • McCarthy, F., Pirvu, D., Hill, J. C., Huang, J., Johnson, M. C., & Rogers, K. K. (2024). Dark photon limits from patchy dark screening of the cosmic microwave background. doi:10.48550/arxiv.2406.02546
  • Mondino, C., Pîrvu, D., Huang, J., & Johnson, M. C. (2024). Axion-Induced Patchy Screening of the Cosmic Microwave Background. doi:10.48550/arxiv.2405.08059
  • Yin, W. W., Dai, L., Huang, J., Ji, L., & Ferraro, S. (2024). A New Probe of Cosmic Birefringence Using Galaxy Polarization and Shapes. arxiv:2402.18568v2
  • Pîrvu, D., Huang, J., & Johnson, M. C. (2024). Patchy screening of the CMB from dark photons. Journal of Cosmology and Astroparticle Physics, 2024(01), 019. doi:10.1088/1475-7516/2024/01/019
  • Siemonsen, N., Mondino, C., Egaña-Ugrinovic, D., Huang, J., Baryakhtar, M., & East, W. E. (2023). Dark photon superradiance: Electrodynamics and multimessenger signals. Physical Review D, 107(7), 075025. doi:10.1103/physrevd.107.075025
  • East, W. E., & Huang, J. (n.d.). Dark photon vortex formation and dynamics. Journal of High Energy Physics, 2022(12), 89. doi:10.1007/jhep12(2022)089
  • Hook, A., & Huang, J. (2022). A Mass for the Dual Photon. arxiv:2210.00015v1
  • DeRocco, W., Wegsman, S., Grefenstette, B., Huang, J., & Van Tilburg, K. (2022). First Indirect Detection Constraints on Axions in the Solar Basin. Physical Review Letters, 129(10), 101101. doi:10.1103/physrevlett.129.101101
  • Chiles, J., Charaev, I., Lasenby, R., Baryakhtar, M., Huang, J., Roshko, A., . . . Berggren, K. K. (2022). New Constraints on Dark Photon Dark Matter with Superconducting Nanowire Detectors in an Optical Haloscope. Physical Review Letters, 128(23), 231802. doi:10.1103/physrevlett.128.231802
  • Agrawal, P., Hook, A., Huang, J., & Marques-Tavares, G. (2022). Axion string signatures: a cosmological plasma collider. Journal of High Energy Physics, 2022(1), 103. doi:10.1007/jhep01(2022)103
Seminars
  • Novel string production mechanisms & gravitational wave detectors, New York University, New York, United States, 2025/03/12
  • What is CMB secondary anisotropy?, What is Particle Theory?, 2025/02/27
  • Novel string production mechanisms & gravitational wave detectors, GW in 3rd Generation Mini-Workshop, 2025/02/05
  • Patchy dark screening, New Physics from Old Light: Illuminating the Universe with CMB Secondaries, 2024/09/18
  • Patchy dark screening, Fundamental Physics from Future Spectroscopic Surveys, Lawrence Berkeley National Laboratory, Berkeley, United States, 2024/05/08
  • Particle Physics Lecture, Particle Physics , 2024/03/25, PIRSA:24030026
  • Particle Physics Lecture, Particle Physics , 2024/03/22, PIRSA:24030025
  • Particle Physics Lecture, Particle Physics , 2024/03/20, PIRSA:24030024
  • Particle Physics Lecture, Particle Physics , 2024/03/18, PIRSA:24030023
  • Particle Physics Lecture, Particle Physics , 2024/03/15, PIRSA:24030022
  • Particle Physics Lecture, Particle Physics , 2024/03/13, PIRSA:24030021
  • Cosmological dynamics of light dark bosons , Colloquium, 2024/02/28, PIRSA:24020048
  • Berry phase in the sky, Shanghai Jiao Tong University, TD Lee institute, Shanghai, China, 2023/12/14
  • Patchy Dark Screening, The 32nd Texas Symposium on Relativistic Astrophysics, Shanghai Jiao Tong University, Shanghai, China, 2023/12/11
  • A New Pulsar, Peking University, Beijing, China, 2023/12/05
  • Patchy dark screening, Tsinghua University, Beijing, China, 2023/12/05
  • Patchy dark screening, University of Oxford, Oxford, United Kingdom, 2023/11/16
  • Patchy dark screening, New physics from galaxy clustering, International Centre for Theoretical Physics, Trieste, Italy, 2023/11/07
  • Vortices destroy U(1) dark photon dark matter, Fermilab, Batavia, United States, 2023/10/19
  • Patchy dark screening, University of Washington, Seattle, United States, 2023/09/26
  • Dark photon vortices, PTI x QMETRO, University of California, Santa Barbara, KITP, Santa Barbara, United States, 2023/09/18
  • Vortex formation depletes dark photon dark matter, Korea Institute for Advanced Study, Seoul, South Korea, 2023/08/03
  • A Camera into the dark Universe, david dunlup observatory, toronto, Canada, 2023/06/24
  • LAMPOST: First Constraints on Dark Photon Dark Matter with an Optical Haloscope, Canadian Association of Physicists, Ottawa, Canada, 2023/06/20
  • Defects of light boson, Galileo Galilei Institute for Theoretical Physics, Florence, Italy, 2023/05/26
  • A new pulsar, Canadian Institute for Advanced Research, Canmore, Canada, 2023/05/11
  • A new pulsar, University of Minnesota, Physics, Minneapolis, United States, 2023/04/14
  • Vortex formation depletes dark photon dark matter, Harvard University, Cambridge, United States, 2023/04/12
  • Particle Physics Lecture - 230331, Particle Physics (2022/2023), 2023/03/31, PIRSA:23030068
  • Particle Physics Lecture - 230329, Particle Physics (2022/2023), 2023/03/29, PIRSA:23030067
  • Particle Physics Lecture - 230327, Particle Physics (2022/2023), 2023/03/27, PIRSA:23030066
  • Particle Physics Lecture - 230324, Particle Physics (2022/2023), 2023/03/24, PIRSA:23030065
  • Particle Physics Lecture - 230322, Particle Physics (2022/2023), 2023/03/22, PIRSA:23030064
  • Particle Physics Lecture - 230320, Particle Physics (2022/2023), 2023/03/20, PIRSA:23030063
  • A new pulsar, Stony Brook University, SCGP, Stony Brook, United States, 2023/03/07
  • A new pulsar, Stanford University, SITP, Stanford, United States, 2023/02/10
  • A new pulsar, University of Chicago, Chicago, United States, 2023/02/08
  • Magnetic mass of the photon, Shanghai Jiao Tong University, TD Li Institute, Shanghai, China, 2022/12/17
  • Welcome & Opening Remarks, School on Table-Top Experiments for Fundamental Physics, 2022/09/19, PIRSA:22090001
  • Vortices deplete dark photons, Dark Matter in Compact Objects, Stars, and in Low Energy Experiments, University of Washington, institute for nuclear theory, Seattle, United States, 2022/08/25, Video URL