  Nonequilibrium many-body transient dynamics play an important role in the
adaptation of active matter systems environment changes. However, the generic
universal behavior of such dynamics is usually elusive and left as open
questions. Here, we investigate the transient dynamics of vortex-like states in
a two-dimensional active matter system that consists of self-propelled
particles with alignment interactions subjected to extrinsic environmental
noise. We identify a universal power-law scaling for the average lifetime of
vortex-like states with respect to the speed of the self-propelled particles.
This universal scaling behavior manifests strong robustness against the noise,
up to the level where influences from environmental fluctuations are large
enough to directly randomize the moving directions of particles. Direct
experimental observations can be readily performed by related experimental
setups operated at a decently low noise level.
