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Strain pattern in supercooled liquids

Investigations of strain correlations at the glass transition reveal unexpected phenomena. The shear strain fluctuations show an Eshelby-strain pattern ($\,\sim \cos{(4θ)}/r^2\,$), characteristic for elastic response, even in liquids at long times [1]. We address this using a mode-coupling theory for the strain fluctuations in supercooled liquids and data from both, video microscopy of a two-dimensional colloidal glass former and simulations of Brownian hard disks. We show that long-ranged and long-lived strain-signatures follow a scaling law valid close to the glass transition. For large enough viscosities, the Eshelby-strain pattern is visible even on time scales longer than the structural relaxation time $τ$ and after the shear modulus has relaxed to zero.