systems in the context of the fractional quantum Hall effect [@Son:2005rv; @Son:2013rqa; @Geracie:2014nka] (see also [@Jensen:2014wha; @Banerjee:2015tga] and references therein).

Other non-relativistic theories such as non-relativistic superstrings and superbranes were studied as special points in the parameter space of M-theory [@Gomis:2000bd; @Danielsson:2000gi], and non-relativistic strings also attracted attention due to the fact that they appear as a possible soluble sector within string theory or M-theory [@Gomis:2004pw; @Gomis:2005pg].

On the other hand, there also exists another type of non-relativistic symmetry that has sporadically attracted some interest over recent years: The Carroll symmetries, which arise when the velocity of light is sent to zero ($c \rightarrow 0$, ultra-relativistic limit) [@LL; @Bacry:1968zf]. The Carroll group introduced by Lévy-Leblond emerged as the ultra-relativistic contraction of the Poincaré group, dual to the non-relativistic contraction leading to the Galilean group. In the Carroll case, at each point of spacetime the light cone collapses to the time axis, whereas in the Galilei case it coincides with the space axis.

Models with Carroll symmetries occurred in the study of tachyon condensation [@Gibbons:2002tv] and also appeared in the study of warped conformal field theories [@Hofman:2014loa] and in the context of tensionless strings [@Bagchi:2013bga; @Bagchi:2015nca; @Bagchi:2016yyf; @Bagchi:2017cte; @Bagchi:2018wsn].

In [@Hartong:2015xda; 