Title: From cosmic lasagna to space-time spaghetti — obtaining the least-model-dependent strong gravitational lensing probe

In this talk, I will introduce those properties of a light-deflecting cosmic structure that can be uniquely and directly determined from observables without any lens model assumptions. These properties constitute the maximum information common to all model-based mass maps and require less than a second of computing time [1]. The derivation of these characteristics also reveals the most general class of lensing degeneracies and a simple physical interpretation of their origins [2].

I will showcase the power of this approach in two galaxy clusters: we can infer a least-model-dependent smoothness scale for dark matter, reconstruct the morphology of the lensed source galaxy, and even infer global properties of the lensing cluster in combination with complementary data [3,4]. Thus, with an increasing amount of data, this approach will allow us to gain a deeper understanding of the _necessary_ amount and properties of dark matter in cosmic structures.

References:
[1] https://arxiv.org/abs/1906.05285
[2] https://arxiv.org/abs/1809.03505, https://arxiv.org/abs/1904.07239, https://arxiv.org/abs/2203.06190
[3] https://arxiv.org/abs/2105.04562, https://arxiv.org/abs/2207.01630
[4] https://arxiv.org/abs/2306.11779