Dark Matter Depletion Corridors as Technosignatures: A Mechanism-Independent Search Strategy Using Weak Gravitational Lensing

We propose a class of technosignature that has received essentially no attention: persistent corridors of reduced dark matter density in galactic halos, produced by any technology that actively removes or expels dark matter along its path. We argue that the depletion signature is physically distinct from, and should not be confused with, the gravitational overdensity wake that a passively transiting mass produces through dynamical friction. A depletion corridor is the specific signature of active dark matter removal, not of generic transit, which makes it a sharper discriminant. Because dark matter is collisionless, such a corridor would refill only through gravitational relaxation, persisting on timescales from roughly 10^7 to 10^9 years depending on corridor width and local velocity dispersion — far longer than any baryonic or electromagnetic signature. We show that the expected morphology is distinct from known astrophysical structures and from the natural dark matter substructure that current surveys already probe, and we describe a detection pipeline based on the Hough transform applied to weak-lensing convergence maps, with an explicit treatment of the false-positive problem. The proposal is conditional and mechanism-independent: it assumes only that some technology removes dark matter during transit, and asks what that would look like and how to search for it in existing public data (DES Y3, DECADE+DES Y3) and forthcoming surveys (Euclid, Rubin/LSST).