“…García-Juárez, Mori, and Strain considered the case where the fluids in the interior and the exterior of the string can have different viscosities, and they showed global well-posedness for initial data of medium size in the critical Wiener space F 1,1 (T) [46]. In [47], Gancedo, Granero-Belinchón, and Scrobogna introduced a toy scalar model that captures the string motion in the normal direction only, for which they proved global well-posedness for small initial data in the critical Lipschitz class W 1,∞ (T). Recently, Chen and Nguyen established well-posedness of the original 2-D Peskin problem in the critical space Ḃ1…”