  Pioneered by Benczur and Karger for cuts in graphs [STOC'96], sparsification
is a fundamental topic with wide-ranging applications that has been studied,
e.g., for graphs and hypergraphs, in a combinatorial and a spectral setting,
and with additive and multiplicate error bounds. Rafiey and Yoshida recently
considered sparsification of decomposable submodular functions [AAAI'22]. We
extend their work by presenting an efficient algorithm for a sparsifier for
monotone $k$-submodular functions of low curvature.
