An Elementary Proof of Eigenvalue Preservation for the Co-rotational Beris-Edwards System

We study the corotational Beris-Edwards system modeling nematic liquid crystals and revisit the eigenvalue preservation property discussed in Wu et al. (Arch Rational Mech Anal, 2018 . https://doi.org/10.1007/s00205-018-1297-2 ). We give an alternative but direct proof to the eigenvalue preservation of the initial data for the Q -tensor. It is noted that our proof is not only valid in the whole-space case, but in the bounded-domain case as well.