Interferometric Signatures of Collectivity in Small Systems

Particle interferometry has proven to be an indispensable tool in probing the space-time evolution of femtoscopic collision systems. In this talk, I show how hydrodynamic predictions for the space-time evolution of high-multiplicity p$+$p and p$+$Pb collisions can be tested against interferometric observables designed to probe their size and shape. In particular, I consider how the dependence of these observables on the multiplicity $dN_{ch}/d\eta $ may reflect the hydrodynamic nature of the evolving system.