Flow measurements in p+Pb and their comparison with Pb+Pb at ATLAS

Particle anisotropic flow observed in the collisions of heavy nuclei is one of the signals of creation of the Quark-Gluon Plasma. The analysis of $p$+Pb collisions at $\sqrt{s_{_{\rm NN}}}=5.02$ TeV provides an opportunity to study the interactions between nucleons in a much smaller volume, but unlike the $pp$ collisions, affected by nuclear effects. This report describes measurements of flow harmonics, $v_{1}$ to $v_{4}$, and their dependence on event centrality and particle transverse momentum.