Alex Krolewski profile photo

University of Waterloo

Affiliate

Areas of research: Cosmology Particle Physics

Research Interests
I am a cosmologist interested in mapping the buildup of cosmic structure and testing gravity and the standard cosmological model on the largest scales. In particular I use gravitational lensing of the cosmic microwave background to constrain the amplitude and growth of structure formation. I am also interested in other CMB secondary anisotropies such as the Sunyaev-Zel'dovich effect; galaxy formation and evolution; exploiting the combined power of photometric and spectroscopic surveys; and the intergalactic medium. I am a member of the DESI, Simons Observatory, and CMB S4 collaborations.
Positions Held
  • AMTD Fellow, University of Waterloo, 2020-present
  • PhD Astrophysics, University of California Berkeley, 2015-2020
Recent Publications
  • Farren, G. S., Krolewski, A., MacCrann, N., Ferraro, S., Abril-Cabezas, I., An, R., . . . Wollack, E. J. (2023). The Atacama Cosmology Telescope: Cosmology from cross-correlations of unWISE galaxies and ACT DR6 CMB lensing. doi:10.3847/1538-4357/ad31a5
  • Hadzhiyska, B., Yuan, S., Blake, C., Eisenstein, D. J., Aguilar, J., Ahlen, S., . . . Zhou, Z. (2023). Synthetic light-cone catalogues of modern redshift and weak lensing surveys with abacussummit. Monthly Notices of the Royal Astronomical Society, 525(3), 4367-4387. doi:10.1093/mnras/stad2563
  • Zhang, B., Lee, K. -G., Krolewski, A., Shi, J., Horowitz, B., & Kooistra, R. (2023). Alignments between Galaxies and the Cosmic Web at z ~ 1–2 in the IllustrisTNG Simulations. The Astrophysical Journal, 954(1), 49. doi:10.3847/1538-4357/ace695
  • Ruggeri, R., Blake, C., DeRose, J., Garcia-Quintero, C., Hadzhiyska, B., Ishak, M., . . . Tarlé, G. (2023). A data compression and optimal galaxy weights scheme for Dark Energy Spectroscopic Instrument and weak lensing data sets. Monthly Notices of the Royal Astronomical Society, 525(3), 3865-3878. doi:10.1093/mnras/stad1651
  • Han, J. J., Dey, A., Price-Whelan, A. M., Najita, J., Schlafly, E. F., Saydjari, A., . . . Zucker, C. (2023). NANCY: Next-generation All-sky Near-infrared Community surveY. arxiv:2306.11784v1
  • Collaboration, D. E. S. I., Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Aldering, G., . . . Zu, Y. (2023). Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument. doi:10.5281/zenodo.7858207
  • Yu, J., Zhao, C., Gonzalez-Perez, V., Chuang, C. -H., Brodzeller, A., Mattia, A. D., . . . Zou, H. (2023). The DESI One-Percent Survey: Exploring A Generalized SHAM for Multiple Tracers with the UNIT Simulation. arxiv:2306.06313v4
  • Hadzhiyska, B., Yuan, S., Blake, C., Eisenstein, D. J., Aguilar, J. N., Ahlen, S., . . . Zhou, Z. (2023). Synthetic light cone catalogues of modern redshift and weak lensing surveys with AbacusSummit. arxiv:2305.11935v1
  • Bolliet, B., Hill, J. C., Ferraro, S., Kusiak, A., & Krolewski, A. (2023). Projected-field kinetic Sunyaev-Zel'dovich Cross-correlations: halo model and forecasts. Journal of Cosmology and Astroparticle Physics, 2023(03), 039. doi:10.1088/1475-7516/2023/03/039
  • Kusiak, A., Bolliet, B., Krolewski, A., & Hill, J. C. (2022). Constraining the galaxy-halo connection of infrared-selected unWISE galaxies with galaxy clustering and galaxy-CMB lensing power spectra. Physical Review D, 106(12), 123517. doi:10.1103/physrevd.106.123517
  • Horowitz, B., Lee, K. -G., Ata, M., Müller, T., Krolewski, A., Prochaska, J. X., . . . Lemaux, B. C. (2022). Second Data Release of the COSMOS Lya Mapping and Tomography Observations: The First 3D Maps of the Detailed Cosmic Web at 2.05 < z < 2.55. The Astrophysical Journal Supplement Series, 263(2), 27. doi:10.3847/1538-4365/ac982d
  • Zhang, B., Lee, K. -G., Krolewski, A., Shi, J., Horowitz, B., & Kooistra, R. (2022). Alignments Between Galaxies and the Cosmic Web at $z \sim 1-2$ in the IllustrisTNG Simulations. doi:10.48550/arxiv.2211.09331
  • Collaboration, D., Abareshi, B., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., . . . Zu, Y. (2022). Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument. The Astronomical Journal, 164(5), 207. doi:10.3847/1538-3881/ac882b
  • Ding, Z., Chuang, C. -H., Yu, Y., Garrison, L. H., Bayer, A. E., Feng, Y., . . . Poppett, C. (2022). The DESI N-body Simulation Project – II. Suppressing sample variance with fast simulations. Monthly Notices of the Royal Astronomical Society, 514(3), 3308-3328. doi:10.1093/mnras/stac1501
  • Krolewski, A., & Ferraro, S. (2022). The Integrated Sachs Wolfe effect: unWISE and Planck constraints on dynamical dark energy. Journal of Cosmology and Astroparticle Physics, 2022(04), 033. doi:10.1088/1475-7516/2022/04/033
  • Collaboration, T. C. -H., :., Aiola, S., Akrami, Y., Basu, K., Boylan-Kolchin, M., . . . Wu, K. (2022). Snowmass2021 CMB-HD White Paper. doi:10.48550/arxiv.2203.05728
  • Mukherjee, S., Krolewski, A., Wandelt, B. D., & Silk, J. (2022). Cross-correlating dark sirens and galaxies: constraints on $H_0$ from GWTC-3 of LIGO-Virgo-KAGRA. doi:10.3847/1538-4357/ad7d90
Seminars
  • CMB lensing cross-correlations on large scales: a clean probe of primordial non-Gaussianity with DESI qusaars and Planck lensing, CMB S4 Collaboration Meeting, SLAC National Accelerator Laboratory, Menlo Park, United States, 2023/08/01
  • Constraining primordial non-Gaussianity from photometric DESI quasar targets and Planck CMB lensing, Future Science with CMB x LSS, Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto, Japan, 2023/04/12
  • Constraining primordial non-Gaussianity from photometric DESI quasar targets and Planck CMB lensing, DESI Collaboration Meeting, December 2022, Cancun, Mexico, 2022/12/06