Mike Hudson — click to apply a gravitational lens

Mike Hudson

Professor of Astrophysics & Cosmology

My research is in observational cosmology and galaxy formation and evolution. I measure the properties of dark matter and dark energy through gravitational lensing and cosmic flows, and I try to determine why galaxies make — and stop making — stars.

Publications (ADS) CV

Research

Questions that drive the work

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What is dark matter?

How much of it is there, and what are its properties? Read more →

Large-scale structure and cosmic flows

How is matter — dark and luminous — distributed across the cosmos, and how fast is structure growing? Read more →

Galaxies and halos

How are galaxies related to the dark-matter halos in which they live, and how do they co-evolve? Read more →

Quenching of star formation in galaxies

Why do some galaxies keep forming stars while others quench, and how fast does it happen when they fall into a cluster? Read more →

Techniques

Three complementary probes

I attack these questions with three observational handles on dark matter and structure formation.

Dark-matter web filaments connecting galaxy halos

Gravitational lensing

Background galaxies appear subtly distorted by the mass — mostly dark matter — along the line of sight. By stacking the distortions of millions of galaxies we can map that mass directly. My group leads the weak-lensing analysis of the UNIONS survey and contributes to Euclid. Read more →

Large-scale structure and cosmic flows

Galaxies trace the dark-matter density field and move in response to it. Comparing observed peculiar velocities to predictions from galaxy redshift surveys is a direct, low-redshift probe of how fast structure is growing. Explore the interactive 3D model of superclusters in the nearby universe we built from the 2M++ catalogue. Read more →

Word cloud from Hudson papers

Orbit libraries

When a galaxy falls into a group or cluster, its orbital history determines when and how it stops forming stars. We use N-body simulations to build a statistical map between observed phase-space coordinates and orbital histories, then fit simple models of stripping and quenching to large galaxy samples to measure when and how fast the quenching happens. Read more →

The Hudson group

Postdocs and graduate students at the Waterloo Centre for Astrophysics

The Hudson group, July 2024

L–R: Ariel Broderick, Martine Campbell, Mike Hudson, Darshak Patel, Pierre Burger, Ian Roberts, Amber Hollinger (July 2024)

Current group

Jack Elvin-Poole

Canadian Rubin Postdoctoral Fellow

Ian Roberts

Banting Postdoctoral Fellow

Jiapeng Zhang

Ph.D. candidate

Hardik Kuralkar

Ph.D. candidate

Joining the group

I welcome applications for graduate positions. Essential prerequisites are an undergraduate degree in physics/astronomy and experience with coding; undergraduate research (e.g. a senior honours thesis) is a bonus. Undergrads should consult the Department's page on Undergraduate Research Awards.

Alumni

Selected former students and postdocs (* = co-supervised).

NameDegree / PositionYearCurrent position
Pierre BurgerPostdoc2025Machine Learning Scientist at SOVRA
Hunter MartinPh.D.2025Postdoc at U Cincinnati
Martine CampbellM.Sc.2025Ph.D. candidate, Barcelona
Darshak PatelM.Sc.2025
Amber HollingerPh.D.2024Postdoc at Australian National University
Jordan DucatelM.Sc.*2024Product Information Analyst at Grainger
Andrew ReevesPh.D.2023Postdoc at York University
Isaac SpitzerPh.D.2022Software Engineer at STScI
Supranta BoruahPh.D.*2020Postdoc at U. Penn
Kyle OmanM.Sc.2013Faculty, Durham University
Laura ParkerPh.D.2005Faculty, McMaster University
…plus many more — view the full alumni list →

News & highlights

Recent press coverage

April 12, 2017

First "image" of a dark-matter web connecting galaxies

Astrophysicists Mike Hudson and Seth Epps captured the first composite image of a dark-matter bridge connecting galaxies. Read the paper.

April 24, 2015

3D master map of the universe

A spherical map of galaxy superclusters spanning nearly two billion light-years — the most complete picture of our cosmic neighbourhood to date.