The mechanism of energy accumulation in dynamic pulses traveling through checkerboard material assembly in space-time

The paper examines the propagation of unilateral waves through an assembly of two materials with different space- and time-dependent properties. The assembly is immovable and characterized by a checkerboard material geometry in space and time. For a special range of material and structural parameters, the checkerboard geometry secures spatiotemporal focusing of traveling waves into progressively compressing pulses accumulating their wave energy along the way.