[1] Duan, Huagui; Xie, Dong, Multiple closed characteristics on compact star-shaped hypersurface. Trans. Amer. Math. Soc. 379 (2026),no. 7,4925-4944.
[2] Duan, Huagui; Xie, Dong, Multiple closed geodesics on a sphere of odd dimension, J. Differential Geom. 133 (2026), no. 1, 1–13.
[3] Duan, Huagui; Fan, Zhiping,Multiple closed characteristics on compact star-shaped hypersurfaces in R10. J. Differential Equations, 465 (2026), Paper No. 114207, 31 pp.
[4] Duan, Huagui; Xie, Dong,On the minimal number of closed geodesics on positively curved Finsler spheres. J. Reine Angew. Math. 830 (2026), 259–283.
[5] Duan, Huagui; Xie, Dong,Four closed characteristics on compact star-shaped hypersurfaces in R8. J. Geom. Anal. 35 (2025), no. 10, Paper No. 289, 14 pp.
[6] Duan, Huagui; Liu, Hui; Long, Yiming; Qi, Zihao; Wang, Wei,Three closed characteristics on non-degenerate star-shaped hypersurfaces in R6.J. Differential Equations, 446 (2025), Paper No. 113605, 30 pp.
[7] Duan, Huagui; Qi, Zihao,Multiple closed geodesics on Finsler 3-dimensional sphere. J. Funct. Anal. 288 (2025), no. 10, Paper No. 110863, 17 pp.
[8] Duan, Huagui; Liu, Hui; Long, Yiming; Wang, Wei,Generalized common index jump theorem with applications to closed characteristics on star-shaped hypersurfaces and beyond. J. Funct. Anal. 286 (2024), no. 7, Paper No. 110352, 41 pp.
[9] Duan, Huagui; Xie, Dong,Multiplicity of closed geodesics on bumpy Finsler manifolds with elliptic closed geodesics. J. Funct. Anal. 284 (2023), no. 8, Paper No. 109861, 20 pp.
[10] Duan, Huagui; Liu, Hui; Ren, Wenyan,A dichotomy result for closed characteristics on compact star-shaped hypersurfaces in R2n. Math. Z. 302 (2022), no. 2, 743–757.
[11] Duan, Hua Gui; Liu, Hui, The non-contractibility of closed geodesics on Finsler RPn. Acta Math. Sin. (Engl. Ser.) 38 (2022), no. 1, 1–21.
[12] Duan, Huagui; Long, Yiming; Zhu, Chaofeng,Index iteration theories for periodic orbits: old and new. Nonlinear Anal. 201 (2020), 111999, 26 pp.
[13] Duan, Huagui; Liu, Hui; Long, Yiming; Wang, Wei, Non-hyperbolic closed characteristics on non-degenerate star-shaped hypersurfaces in R2n. Acta Math. Sin. (Engl. Ser.) 34 (2018), no. 1, 1–18.
[14] Duan, Huagui;Liu,Hui, Multiplicity and ellipticity of closed characteristics on compact star-shaped hypersurfaces in R2n. Calc. Var. Partial Differential Equations, 56 (2017), no. 3, Paper No. 65, 30 pp.
[15] Duan, Huagui; Long, Yiming; Wang, Wei,The enhanced common index jump theorem for symplectic paths and non-hyperbolic closed geodesics on Finsler manifolds. Calc. Var. Partial Differential Equations, 55 (2016), no. 6, Art. 145, 28 pp.
[16] Duan, Huagui; Long, Yiming; Wang, Wei,Two closed geodesics on compact simply connected bumpy Finsler manifolds. J. Differential Geom. 104 (2016), no. 2, 275–289.
[17] Duan, Huagui,Two elliptic closed geodesics on positively curved Finsler spheres. J. Differential Equations, 260 (2016), no. 12, 8388–8402.
[18] Duan, Huagui; Liu, Hui, Multiplicity of closed geodesics on Finsler spheres with irrationally elliptic closed geodesics. Sci. China Math. 59 (2016), no. 3, 531–538.
[19] Duan, Huagui; Liu, Hui, Closed geodesics on positively curved Finsler 3-spheres. Adv. Nonlinear Stud. 16 (2016), no. 1, 159–171.
[20] Duan, Huagui; Long, Yiming; Xiao, Yuming,Two closed geodesics on RP2n+1 with a bumpy Finsler metric. Calc. Var. Partial Differential Equations, 54 (2015), no. 3, 2883–2894.
[21] Duan, Huagui,Non-hyperbolic closed geodesics on positively curved Finsler spheres. J. Funct. Anal. 269 (2015), no. 11, 3645–3662.
[22] Duan, Huagui; Liu, Hui, The irrational ratio of average indices of closed geodesics on positively curved Finsler spheres. Nonlinear Anal. 128 (2015), 36–47.
[23] Duan, Huagui;Long,Yiming, The index growth and multiplicity of closed geodesics. J. Funct. Anal. 259 (2010), no. 7, 1850–1913.
[24] Long, Yiming; Duan, Huagui,Multiple closed geodesics on 3-spheres. Adv. Math. 221 (2009), no. 6, 1757–1803.
[25] Duan, Huagui; Long, Yiming, Morse concavity for closed geodesics. Acta Math. Sci. Ser. B (Engl. Ed.) 29 (2009), no. 3, 731–750.
[26] Duan, Huagui; Long, Yiming,Multiplicity and stability of closed geodesics on bumpy Finsler 3-spheres. Calc. Var. Partial Differential Equations, 31 (2008), no. 4, 483–496.
[27] Duan, Huagui; Long, Yiming,Multiple closed geodesics on bumpy Finsler n-spheres. J. Differential Equations, 233 (2007), no. 1, 221–240.