  In this paper, we propose a Minimax Trust Region (MINIMAX-TR) algorithm and a
Minimax Trust Region Algorithm with Contractions and Expansions(MINIMAX-TRACE)
algorithm for solving nonconvex-strongly concave minimax problems. Both
algorithms can find an $(\epsilon, \sqrt{\epsilon})$-second order stationary
point(SSP) within $\mathcal{O}(\epsilon^{-1.5})$ iterations, which matches the
best well known iteration complexity.
