In my talk, I will present the so-called slingshot effect. It represents a general phenomenon that occurs when a localized source, such as a magnetic monopole, quark, or a D-brane, crosses a wall separating the confined (Higgsed) and unconfined (Coulomb) phases. The crossover is accompanied by a stretched string that confines the source to the wall. The string tension accelerates the source towards the wall as sort of a slingshot. The effect can take place in different setups, such as phase transitions leading to both electric and magnetic confinement, as well as in string cosmology involving D-branes. I will discuss the role of this phenomenon in sourcing gravitational waves. 
https://indico.ijs.si/event/3895/