Matthew Johnson

Research Interests

The goal of my research is to understand the fundamental laws of nature through their impact on cosmology. I am primarily a theorist, dabbling in cosmology, field theory, string theory, and gravitation. I also design data analysis algorithms to confront fundamental theory with observations of the Cosmic Microwave Background (CMB) radiation. Here is a sampling of questions that my research aims to answer: How big is the universe? What might lie beyond our observable universe, and how could we confirm or disprove various proposals? What role do the extra dimensions predicted by string theory play in cosmology? Are there new ways of looking at cosmological datasets that could be useful when confronting theories with data? Can computer simulations of the very early universe shed light on it's possible initial conditions and evolution?

Positions Held

• 2017-present York University and Perimeter Institute, Associate Professor 2012 - 2017 York University and Perimeter Institute, Assistant Professor 2010 - 2012 Perimeter Institute for Theoretical Physics, Postdoctoral Scholar 2007 - 2010 California Institute of Technology, Moore Postdoctoral Scholar

Recent Publications

• Jonathan Braden, Matthew C. Johnson, Hiranya V. Peiris, and Anthony Aguirre, Constraining cosmological ultra-large scale structure using numerical relativity, Phys. Rev. D96, 023541 (2017), arXiv: 1604.04001.
• Chad Hanna, Matthew C. Johnson, and Luis Lehner, Estimating gravitational radiation from super-emitting compact binary systems, Phys. Rev. D95, 124042 (2017), arXiv: 1611.03506.
• Alexandra Terrana, Mary-Jean Harris, and Matthew C. Johnson, Analyzing the cosmic variance limit of remote dipole measurements of the cosmic microwave background using the large-scale kinetic Sunyaev Zel"dovich effect, Journal of Cosmology and Astroparticle Physics (JCAP) 02 040 (2017), arXiv: 1610.06919.
• Matthew C. Johnson, Carroll L. Wainwright, Hiranya V. Peiris, and Anthony Aguirre, Simulating the universe(s) III: Observables for the full bubble collision spacetime, Journal of Cosmology and Astroparticle Physics (JCAP) 07 020 (2016), arXiv: 1508.03786.
• Matthew C. Johnson and Wei Lin, Observable signatures of classical transitions, JCAP 03 051 (2016), arXiv: 1508.03786.
• Stephen M. Feeney, Franz Elsner, Matthew C. Johnson, and Hiranya V. Peiris, Forecasting constraints from the cosmic microwave background radiation on eternal inflation, Phys. Rev. D92, 083515 (2015), arXiv: 1506.01716.
• Matthew C. Johnson and Alexandra Terrana, Tensor modes in bigravity: primordial to present, arXiv: 1503.05560 (2015). Phys. Rev. D 92, 044001 (2015), arxiv:1503.05560.
• Pengjie Zhang and Matthew C. Johnson, Testing eternal inflation with the kinetic Sunaev Zel'dovich effect, Journal of Cosmology and Astroparticle Physics (JCAP) 06 046 (2015), arXiv: 1501.00511.
• Richard Brito, Alexandra Terrana, Matthew C. Johnson, and Vitor Cardoso, The nonlinear dynamical stability of infrared modifications of gravity, Phys. Rev. D90, 124035 (2014). arXiv: 1409.0886
• Carroll L. Wainwright, Matthew C. Johnson, Hiranya V. Peiris, and Anthony Aguirre, Simulating the universe(s) II: phenomenology of cosmic bubble collisions in full General Relativity, JCAP 10 024 (2014), arXiv: 1407.2950.
• Carroll L. Wainwright, Matthew C. Johnson, Hiranya V. Peiris, Anthony Aguirre, Luis Lehner, and Steven L. Liebling, Simulating the universe(s): from cosmic bubble collisions to cosmological observables with numerical relativity, JCAP 03 030 (2014). arXiv: 1312.1357
• Stephen M. Feeney, Matthew C. Johnson, Jason D. McEwan, Daniel J. Mortlock, Hiranya V. Peiris, Hierarchical Bayesian Detection Algorithm for Early-Universe Relics in the Cosmic Microwave Background, Phys. Rev. D88, 043012 (2013). arXiv: 1210.2725
• Stephen M. Feeney, Matthew C. Johnson, Daniel J. Mortlock, Hiranya V. Peiris, A robust constraint on cosmic textures from the cosmic microwave background, Phys.Rev.Lett. 108, 241301 (2012), arXiv: 1203.1928.
• Matthew C. Johnson and Jean-Luc Lehners, Cycles in the Multiverse, Phys.Rev. D85, 103509 (2012), arXiv: 1112.3360.
• Jason D. McEwen, Stephen M. Feeney, Matthew C. Johnson, Hiranya V. Peiris, Optimal filters for detecting cosmic bubble collisions, Phys.Rev. D85, 103502 (2012), 1202.2861
• Matthew C. Johnson, Hiranya V. Peiris, Luis Lehner, Determining the outcome of cosmic bubble collisions in full General Relativity, Phys.Rev. D85, 083516 (2012), arXiv: 1112.4487.
• Anthony Aguirre, Sean M. Carroll, Matthew C. Johnson, Out of equilibrium: understanding cosmological evolution to lower-entropy states, JCAP 1202, 024 (2012), arXiv: 1108.0417.
• Stephen M. Feeney, Matthew C. Johnson, Daniel J. Mortlock, Hiranya V. Peiris, First Observational Tests of Eternal Inflation: Analysis Methods and WMAP 7-Year Results, Phys. Rev. D 84, 043507 (2011), arXiv: 1012.3667.
• Stephen M. Feeney, Matthew C. Johnson, Daniel J. Mortlock, Hiranya V. Peiris, First Observational Tests of Eternal Inflation, Phys. Rev. Lett. 107, 071301 (2011), arXiv: 1012.1995.
• Niayesh Afshordi and Matthew C. Johnson, Cosmological Zero Modes, arXiv: 1708.04694 (2017).
• Anne-Sylvie Deutsch, Emmanuela Dimastrogiovanni, Matthew C. Johnson, Moritz Münchmeyer, and Alexandra Terrana, Reconstruction of the remote dipole and quadrupole fields from the kinetic Sunyaev Zel'dovich and polarized Sunyaev Zel'dovich effects, arXiv: 1707.08129 (2017).
• Anne-Sylvie Deutsch, Matthew C. Johnson, Moritz Münchmeyer, and Alexandra Terrana, Polarized Sunyaev Zel'dovich tomography, arXiv: 1705.08907 (2017).
• Testing Inflation with Large Scale Structure: Connecting Hopes with Reality, Marcelo Alvarez, Tobias Baldauf, J. Richard Bond, Neal Dalal, Roland de Putter, Olivier Doré, Daniel Green, Chris Hirata, Zhiqi Huang, Dragan Huterer, Donghui Jeong, Matthew C. Johnson, Elisabeth Krause, Marilena Loverde, Joel Meyers, P. Daniel Meerburg, Leonardo Senatore, Sarah Shandera, Eva Silverstein, Anze Slosar, Kendrick Smith, Matias Zaldarriaga, Valentin Assassi, Jonathan Braden, Amir Hajian, Takeshi Kobayashi, George Stein, Alexander van Engelen, arxiv:astro-ph.CO/1412.4671

Seminars

• Exploring the ultra-large scale structure of the Universe, Advances inTheoretical Cosmology in Light of Data conference at NORDITA
• Mapping ultra large scale structure, Case Western Reserve University
• General relativistic non-linearities in cosmology, 2016 Midwest Relativity Meeting
• Observable non-linearities in cosmology, Canadian Conference on General Relativity and Relativistic Astrophysics
• General relativistic non-linearities in cosmology, GR21 Conference
• Constraining cosmological ultra large scale structure using numerical relativity, Great Lakes Cosmology and Galaxies 2016
• Constraining cosmological ultra large scale structure using numerical relativity, Theory Canada 11
• Constraining inflationary initial conditions, University of Amsterdam
• Searching for other Universes, University of Toronto, Physics Colloquium
• Inverse problems in early Universe cosmology, Fields Institute, Inverse Problems and Image Analysis Seminar
• Testing eternal inflation, Case Western Reserve University
• Searching for other Universes, Carleton University, Physics Colloquium
• Quantum in Cosmology, NASA Blue Sky Meeting on Quantum Technologies
• Searching for other Universes, McMaster University, Physics Colloquium
• Acts of Faith: what we assume, and then forget, about our research, Scifoo conference
• Latest constraints and forecasts for testing eternal inflation, Caltech
• Inferring the Universe, York University Math and Statistics
• Simulating the Universe(s), CITA
• Early Universe Cosmology, CAP Congress
• Simulating the Universe(s), Canadian Conference on General Relativity and Relativistic Astrophysics
• Simulating the Universe(s), Imperial College London
• Eternal Inflation, University of Waterloo
• Eternal Inflation, Quantum Gravity and Fundamental Cosmology Workshop, Albert Einstein Institute, Potsdam Germany
• Searching for early-universe relics in the CMB, McGill University
• PIRSA:16070064, Matthew Johnson ISSYP 2016 Keynote - Searching for Other Universes, 2016-07-22,
• PIRSA:15080112, Introduction to Cosmology - Matt Johnson, 2015-08-28, PSI 2015/2016 Introduction to Cosmology - Matt Johnson
• PIRSA:15080111, Introduction to Cosmology - Matt Johnson, 2015-08-27, PSI 2015/2016 Introduction to Cosmology - Matt Johnson
• PIRSA:15080110, Introduction to Cosmology - Matt Johnson, 2015-08-25, PSI 2015/2016 Introduction to Cosmology - Matt Johnson
• PIRSA:14080035, 14/15 PSI - Differential Geormetry, 2014-08-28,
• PIRSA:14080034, 14/15 PSI - Differential Geormetry, 2014-08-27,
• PIRSA:14080033, 14/15 PSI - Differential Geormetry, 2014-08-26,
• PIRSA:14080032, 14/15 PSI - Differential Geormetry, 2014-08-25,
• PIRSA:14070025, Searching for Other Universes, 2014-07-14, ISSYP 2014
• PIRSA:14070020, EinsteinPlus 2014 - Cosmology Keynote, 2014-07-08, EinsteinPlus 2014
• PIRSA:14040059, 13/14 PSI - Explorations in Cosmology - Lecture 14, 2014-04-25, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040058, 13/14 PSI - Explorations in Cosmology - Lecture 13, 2014-04-24, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040057, 13/14 PSI - Explorations in Cosmology - Lecture 12, 2014-04-23, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040056, 13/14 PSI - Explorations in Cosmology - Lecture 11, 2014-04-22, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040055, 13/14 PSI - Explorations in Cosmology - Lecture 10, 2014-04-21, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040051, 13/14 PSI - Explorations in Cosmology - Lecture 9, 2014-04-17, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040050, 13/14 PSI - Explorations in Cosmology - Lecture 8, 2014-04-16, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040049, 13/14 PSI - Explorations in Cosmology - Lecture 7, 2014-04-15, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040048, 13/14 PSI - Explorations in Cosmology - Lecture 6, 2014-04-14, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040045, 13/14 PSI - Explorations in Cosmology - Lecture 5, 2014-04-11, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040044, 13/14 PSI - Explorations in Cosmology - Lecture 4, 2014-04-10, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040043, 13/14 PSI - Explorations in Cosmology - Lecture 3, 2014-04-09, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040042, 13/14 PSI - Explorations in Cosmology - Lecture 2, 2014-04-08, 13/14 PSI - Explorations in Cosmology
• PIRSA:14040041, 13/14 PSI - Explorations in Cosmology - Lecture 1, 2014-04-07, 13/14 PSI - Explorations in Cosmology
• PIRSA:14010101, Simulating the Universe(s), 2014-01-14, Cosmology & Gravitation
• PIRSA:13070058, Quantum Cosmology - 3, 2013-07-23, Loops 13
• PIRSA:13070029, Searching for Other Universes, 2013-07-08, ISSYP 2013
• PIRSA:13040080, 12/13 PSI - Explorations in Cosmology Lecture 15, 2013-04-26, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040079, 12/13 PSI - Explorations in Cosmology Lecture 14, 2013-04-25, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040078, 12/13 PSI - Explorations in Cosmology Lecture 13, 2013-04-24, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040077, 12/13 PSI - Explorations in Cosmology Lecture 12, 2013-04-23, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040076, 12/13 PSI - Explorations in Cosmology Lecture 11, 2013-04-22, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040073, 12/13 PSI - Explorations in Cosmology Lecture 10, 2013-04-19, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040072, 12/13 PSI - Explorations in Cosmology Lecture 9, 2013-04-18, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040071, 12/13 PSI - Explorations in Cosmology Lecture 8, 2013-04-17, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040070, 12/13 PSI - Explorations in Cosmology Lecture 7, 2013-04-16, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040069, 12/13 PSI - Explorations in Cosmology Lecture 6, 2013-04-15, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040066, 12/13 PSI - Explorations in Cosmology Lecture 5, 2013-04-12, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040065, 12/13 PSI - Explorations in Cosmology Lecture 4, 2013-04-11, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040064, 12/13 PSI - Explorations in Cosmology Lecture 3, 2013-04-10, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040063, 12/13 PSI - Explorations in Cosmology Lecture 2, 2013-04-09, 12/13 PSI - Explorations in Cosmology
• PIRSA:13040062, 12/13 PSI - Explorations in Cosmology Lecture 1, 2013-04-08, 12/13 PSI - Explorations in Cosmology
• PIRSA:12100050, 12/13 PSI Researcher Presentation, 2012-10-24, 12/13 PSI Researcher Presentations
• PIRSA:12020144, Feature-finding in the cosmic microwave background, 2012-02-09, Workshop: Computational Methods at Perimeter
• PIRSA:11010114, Observational tests of eternal inflation, 2011-01-25, Cosmology & Gravitation
• PIRSA:09070023, Dynamical compactification from higher dimensional de Sitter space, 2009-07-16, Holographic Cosmology Conference
• PIRSA:06120021, Bubble Nucleation and Eternal Inflation, 2006-12-05, Young Researchers Conference - 2006