Aymeric Galan

Postdoctoral researcher based in Switzerland

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Department of Astronomy

University of Geneva

Switzerland

I am a postdoctoral researcher at the Department of Astronomy of the University of Geneva (UNIGE), supported by a Swiss National Science Foundation (SNSF) Mobility return grant, since February 2026.

My research focuses on strong gravitational lensing: using the distorted, multiply-imaged light of background sources to study the mass distribution of foreground galaxies, constrain the properties of dark matter, and measure cosmological parameters such as the Hubble constant. I develop and apply analysis tools for lens modeling and time-delay cosmography, and I am a developer of Herculens and a significant contributor to Lenstronomy, two open-source gravitational lensing modeling packages.

Before joining UNIGE, I held postdoctoral positions at the Max Planck Institute for Astrophysics (MPA) and the Technical University of Munich (TUM) (2022–2025, including a first SNSF Postdoc.Mobility fellowship), and at the Laboratory of Astrophysics (LASTRO), EPFL (2022–2023). I completed my PhD at LASTRO, EPFL in 2022, working on next-generation modeling techniques for strong gravitational lensing and measuring the Hubble constant, under the supervision of Prof. Frédéric Courbin (EPFL) and Dr. Jean-Luc Starck (CEA Saclay).

I am a member of the COSMOGRAIL and TDCOSMO collaborations, the Euclid Consortium, and the SLICE project.

Outside of research, I enjoy racket sports and astro- and landscape photography.

news

Feb 01, 2026 Started as a postdoctoral researcher at the Department of Astronomy, University of Geneva (UNIGE), supported by an SNSF Mobility return grant.
Apr 01, 2025 Started a postdoc at the Max Planck Institute for Astrophysics (MPA), working on galaxy evolution with Euclid strong lenses.
Mar 01, 2023 Started as a postdoctoral researcher hosted at the Technische Universität München (UNIGE), supported by an SNSF Mobility grant.

selected publications

  1. TDCOSMO XXVIII. The Hubble constant from the quadruply lensed quasar J1537-3010 with precise time delays
    A. Galan, A. G. Schweinfurth, S. H. Suyu, and 21 more authors
    arXiv e-prints, Aug 2026
  2. A&A
    Strong lensing model and dust extinction maps of the host galaxy of type Ia supernova H0pe
    A. Galan, S. Schuldt, G. B. Caminha, and 8 more authors
    Astronomy & Astrophysics, Apr 2026
    DOI
  3. A&A
    Exploiting the diversity of modeling methods to probe systematic biases in strong lensing analyses
    A. Galan, G. Vernardos, Q. Minor, and 3 more authors
    Astronomy & Astrophysics, Dec 2024
    DOI
  4. A&A
    El Gordo needs El Anzuelo: Probing the structure of cluster members with multi-band extended arcs in JWST data
    A. Galan, G. B. Caminha, J. Knollmüller, and 2 more authors
    Astronomy & Astrophysics, Sep 2024
    DOI
  5. JOSS
    COOLEST: COde-independent Organized LEns STandard
    Aymeric Galan, Lyne Vyvere, Matthew R. Gomer, and 2 more authors
    Journal of Open Source Software, Aug 2023
    DOI
  6. Nat. Astron.
    Strong gravitational lensing by AGNs as a probe of the quasar–host relations in the distant Universe
    Martin Millon, Frédéric Courbin, Aymeric Galan, and 4 more authors
    Nature Astronomy, Jun 2023
    DOI
  7. A&A
    Using wavelets to capture deviations from smoothness in galaxy-scale strong lenses
    A. Galan, G. Vernardos, A. Peel, and 2 more authors
    Astronomy & Astrophysics, Dec 2022
    DOI
  8. A&A
    SLITRONOMY: Towards a fully wavelet-based strong lensing inversion technique
    A. Galan, A. Peel, R. Joseph, and 2 more authors
    Astronomy & Astrophysics, Mar 2021
    DOI
  9. A&A
    TDCOSMO. I. An exploration of systematic uncertainties in the inference of H0 from time-delay cosmography
    M. Millon, A. Galan, F. Courbin, and 8 more authors
    Astronomy & Astrophysics, Jul 2020
    DOI
  10. ASCL
    Herculens: Differentiable gravitational lensing
    Aymeric Galan, Austin Peel, Georgios Vernardos, and 3 more authors
    2022