01 / COSMIC GAS
The intergalactic medium
Using the Lyman-α forest as a precision probe of matter clustering, thermal history, and fundamental physics.
Cosmology · Fundamental Physics · SISSA
Matteo
Viel
Exploring the cosmic web to understand the fundamental nature of our Universe.
Professor of Cosmology in the Astroparticle and Gravitational Physics Group at SISSA. My research connects the intergalactic medium, dark matter, and cosmic structure formation.
Cosmic-web simulation image (supplied by the Sherwood collaboration). Explore Sherwood-Relics · Sherwood.
What I study
Research at the frontier
of cosmology
02 / FUNDAMENTAL PHYSICS
The nature of dark matter
Testing cold, warm, fuzzy, and interacting dark matter models with high-resolution observations and simulations.
03 / COMPUTATION
Cosmological simulations
Modelling nonlinear structure formation and astrophysical processes with numerical and hydrodynamical methods.
04 / COSMIC STRUCTURE
Large-scale structure
Combining diverse tracers to constrain cosmological parameters and the evolution of the Universe.
05 / COSMOLOGICAL PROBES
Intensity mapping
Using line-intensity mapping of neutral hydrogen and other tracers to map large-scale structure, trace cosmic evolution, and constrain cosmological models.
06 / NEW APPROACHES
Inference and new methods
Exploring effective field theories, machine learning, and field-level approaches to cosmological inference.
Latest work
Publications in 2026
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Teaching & resources
Lecture notes
Cosmology, structure formation, the intergalactic medium and fundamental physics. Browse lectures and course materials by topic.
About
Science across
cosmic scales
I am a Full Professor in the Astroparticle Physics Group at SISSA. Previously, I worked at INAF–OATS and held research positions at the Institute of Astronomy, University of Cambridge, and Clare Hall College.
My work uses observations, theory, and simulations to connect small-scale astrophysics with the fundamental properties of the Universe.
Areas of expertise
Lyman-α forestDark matterHydrodynamical simulationsCosmic webCosmological inferenceLarge-scale structureIntensity Mapping
Full CV (PDF) ↗Affiliations
Get in touch
Contact
SISSA — International School for Advanced Studies
Via Bonomea 265, 34136 Trieste, Italy
Office telephone: +39 040 3787 517
Office: Room 511