We consider computing optimal k-norm preemptive schedules of jobs that arrive over time. In particular, we show that computing the optimal k-norm of flow schedule, is strongly NP-hard for k in (0, 1) and integers k in (1, infinity). Further we show that computing the optimal k-norm of stretch schedule, is strongly NP-hard for k in (0, 1) and integers k in (1, infinity).
@article{arxiv.1301.0793,
title = {The Complexity of Scheduling for p-norms of Flow and Stretch},
author = {Benjamin Moseley and Kirk Pruhs and Cliff Stein},
journal= {arXiv preprint arXiv:1301.0793},
year = {2013}
}