Dark Matter under the Gravitational Lens

7 Apr 2025, 09:30 → 10 Apr 2025, 17:45 Asia/Hong_Kong

CMA Lecture Theatre (廠商會演講廳), G/F (Yasumoto International Academic Park)

The aim of this workshop is to bring together experts on and practitioners of gravitational lensing to address the nature of Dark Matter (DM), with a particular (albeit not exclusive) focus on whether DM comprises ultra-massive particles such as WIMPs or ultra-light particles (which manifest themselves on macroscopic scales as waves) such as Axions.  We aim for an honest discourse on the caveats, weaknesses, and ambiguities of each approach, so as to make clear what steps we, as a community, need to take to improve upon the standard of evidence for the nature of DM.  We especially welcome new or novel approaches for placing DM – whatever its hypothesised nature (e.g., warm instead of cold, invisible baryons) or properties (e.g., self-interacting) – under the gravitational lens.  We also plan a special session to address what constraints gravitational lensing of gravitational waves, independent of or in addition to gravitational lensing of electromagnetic waves, may provide on the nature of Dark Matter.

This workshop is funded in large part by the Croucher Foundation, with additional minor support from the University of Hong Kong (HKU) and the Chinese University of Hong Kong (CUHK).  There will be no registration fee. We will provide airfare (up to a limit) and local accommodations for plenary speakers.  We will provide local accommodations for invited speakers, and hopefully, partial support for local accommodations for contributed speakers. We ask speakers who can support conference expenses from their own grants to let us know, allowing us to provide some level of local accommodation support for graduate students.  

Owing to the lack of availability of a conference room at the University of Hong Kong, we have had to move the workshop to the Chinese University of Hong Kong and change the dates of the workshop to Apr 7-10.

The conference photos have now been uploaded to 0407-0410 DM lens photos (link embedded). Feel free to download! Hope to see you again some time somewhere in the universe!

How to get to Yasumoto International Academic Park.pdf

W-Fi Guest Account Information Slip.pdf

Monday 7 April

Duration for each type of talk: Plenary: 35 min + 10 min Q&A; Invited: 20 min + 5 min Q&A; Contributed: 15 min + 5 min Q&A

Registration

Conference Registration

Morning Session: Welcome – Jeremy Lim (SOC Chair)

Morning Session: Plenary 1: Frédéric Courbin (Tracing the History of Gravitational Lensing)

Morning Session: Plenary 2: Richard Massey (Theory of Gravitational Lensing)

12:30 Lunch Break

Afternoon Session 1: Plenary 3: Mengjiao Xiao (Laboratory Experiments)

Afternoon Session 1: Plenary 4: Guillaume Mahler (Astronomical Constraints on Nature of Dark Matter)(online)

15:15 Break

Afternoon Session 2: Invited 1: Leo Fung (Sub-structures Beyond the Diffraction Limit: A Systematic Overview of Techniques in Gravitational Lensing)

Afternoon Session 2: Invited 2: Derek Perera (Advantages and Disadvantages of using Free-form Lens Modelling to constrain Dark Matter)

Afternoon Session 2: Contributed 1: Ruizhe Feng (Lensing anomalies in image positions and flux ratios - baseline statistics on model accuracy)

Afternoon Session 2: Contributed 2: Alex Chow (Type and Level of Lensing Anomalies truly generated by Dark Matter Sub-structures)

Afternoon Session 2: Contributed 3: Daniel Ballard (Double source planes: what are they good for?)

Tuesday 8 April

Morning Session 1: Plenary 5: Justin Read (WIMPs)

Morning Session 1: Plenary 6: Lam Hui (Axions)

10:30 Break

Morning Session 2: Plenary 7: Simona Vegetti (Gravitational Lensing tests of WIMPs)

Morning Session 2: Invited 1: Samuel Lange (Direct detection of dark subhalos: degeneracy with lens mass complexity)

Morning Session 2: Contributed 0: Jess Doppel (Tiny galaxies or dark subhalos: exploring the "dark" side of galaxy groups and clusters in TNG50)

12:30 Lunch Break

Afternoon Session 1: Invited 1: Joaquin Becerra Espinoza (Astrometric Signatures of Dark Matter Subhalos in Galaxy Clusters)

Afternoon Session 1: Invited 2: Daniel Gilman (Constraints on dark matter properties from the JWST lensed quasar dark matter survey)

Afternoon Session 1: Contributed 1: Huimin Qu (Navigating Dark Matter: Reconstructing 16 PISCO Lens Systems for Substructure Insights)

Afternoon Session 1: Invited 1: David Lagattuta (Exotic cluster lenses: a new tool in the search for dark matter)

15:20 Break

Afternoon Session 2: Contributed 1: Nency Patel (Probing Dark Matter with Gravitational Lensing Mass Models: A Case Study of Abell 2744)

Afternoon Session 2: Contributed 2: Maximilian von Wietersheim-Kramsta (Simulation-based inference of dark matter subhaloes and macro models in strong gravitational lenses)

Afternoon Session 2: Contributed 3: Karl Glazebrook (Source complexity and substructure searches)

Afternoon Session 2: WIMP debate

Wednesday 9 April

Morning Session 1: Local Plenary 10: Yiming Zhong (Self-interacting DM)

Morning Session 1: Contributed 1: Siyuan Hou (A Universal Analytic Model for Gravitational Lensing by Self-Interacting Dark Matter Halos)

Morning Session 1: Contributed 3: Wolfgang Enzi (The overconcentrated dark halo in the strong lens SDSS J0946+1006 is a subhalo: evidence for self-interacting dark matter?)

10:25 Break

Morning Session 2: Contributed 2: Richard Massey (Dark Matter particle colliders... in space)

Morning Session 2: Plenary 9: Elisa Ferreira (Axions)

Morning Session 2: Invited 1: Amruth Alfred (Lighting up the Crinkly Spacetime of Dark Matter)

Morning Session 2: Invited 2: Jose Maria Palencia (Wave Dark Matter Insights from Strong Galaxy Lensing)

12:55 Lunch Break - Group picture!

14:05 Conference Hike

Make way to Sai Kung by public bus at attendee’s expense (Information will be provided)
Free time at Sai Kung (recommendation: take ferry to outlying islands at attendee’s expense)

Banquet

Thursday 10 April

Morning Session 1: Plenary 8: Patrick Kelly (Cluster Transients)

Morning Session 1: Invited 1: Adi Zitrin (Recent efforts to study Caustic Crossing Events)

Morning Session 1: Invited 2: Sung Kei Li (Spatial Distribution of Transients as probe of nature of Dark Matter)

10:30 Break

Morning Session 2: Invited 1: Liang Dai (Effects of Subhalos on Interpreting Highly Magnified Sources Near Lensing Caustics)

Morning Session 2: Contributed 1: Wenwen Zheng (GPU-PMO-CAUSTIC: A Microlensing Simulation Code for Caustic Crossing Events in Galaxy Clusters)

Afternoon Session 1: Plenary 11: Justin Janquart (Detections and Searches for Multiply-lensed GWs)

12:30 Lunch Break

Afternoon Session 1: Invited 1: Marek Biesiada (Gravitational lensing and gravitational waves - new opportunities to test dark matter)

Afternoon Session 1: Laura

Afternoon Session 2: Contributed 0: Bin Hu (Monitoring of time delay in gravitational lensing transient sources with the Mutztag 1.93-meter telescope)

Afternoon Session 2: Contributed 1: Benjamin Beauchesne (Multiwavelength views on the mass distribution of galaxy clusters)

15:15 Break

Afternoon Session 2: Closing Remarks: Richard Massey