刘思齐和他的合作者们的研究成果主要集中在可积偏微分方程在一些自然的坐标变换下的分类问题,以及这些分类结果对现代数学物理(如弦理论、镜对称问题等)的应用。具体包括:半单流体力学型双Hamilton 结构的若干分类定理、单分量演化方程的可积性判据和Hamilton性判据、关于Drinfeld-Sokolov系统的若干问题、BCFG型FJRW理论和相应的Witten猜想、偏微分方程的Jacobi结构、半单上同调场论的抽象Hodge积分理论等等。代表性论文如下:
发表论文:
[1] Dubrovin, Boris; Liu, Si-Qi; Yang, Di; Zhang, Youjin. Hodge integrals and tau-symmetric integrable hierarchies of Hamiltonian evolutionary PDEs. Adv. Math. 293 (2016), 382–435.
[2] Liu, Si-Qi; Ruan, Yongbin; Zhang, Youjin. BCFG Drinfeld-Sokolov hierarchies and FJRW-theory. Invent. Math. 201 (2015), no. 2, 711–772.
[3] Liu, Si-Qi; Zhang, Youjin. Bihamiltonian cohomologies and integrable hierarchies I: A special case. Comm. Math. Phys. 324 (2013), no. 3, 897–935.
[4] Liu, Si-Qi; Zhang, Youjin. Jacobi structures of evolutionary partial differential equations. Adv. Math. 227 (2011), no. 1, 73–130.
[5] Dubrovin, Boris; Liu, Si-Qi; Zhang, Youjin. Frobenius manifolds and central invariants for the Drinfeld-Sokolov bi-Hamiltonian structures. Adv. Math. 219 (2008), no. 3, 780–837.
[6] Dubrovin, Boris; Liu, Si-Qi; Zhang, Youjin. On Hamiltonian perturbations of hyperbolic systems of conservation laws. I. Quasi-triviality of bi-Hamiltonian perturbations. Comm. Pure Appl. Math. 59 (2006), no. 4, 559–615.