Reseach

1. Sugiyama, Yuusuke, Nonexistence of global solution to some second order quasilinear hyperbolic equation, SUT Journal of Mathematics 47, no. 2, 217--227, 2011

2. Kato, Keiichi; Sugiyama, Yuusuke, Local existence and uniqueness theory for the second sound equation in one space dimension, Journal of Hyperbolic Differential Equations 9, no. 1, 177--193, 2012.

3. Kato, Keiichi; Sugiyama, Yuusuke, Blow up of solutions to the second sound equation in one space dimension, Kyushu Journal of Mathematics 67, no. 1, 129--142, 2013.

4. Sugiyama, Yuusuke, Global existence of solutions to some quasilinear wave equation in one space dimension, Differential and Integral Equations 26, no. 5-6, 487--504, 2013.

5. Yamamoto, Masakazu; Kato, Keiichi; Sugiyama, Yuusuke, Existence and analyticity of solutions to the drift-diffusion equation with critical dissipation, Hiroshima Mathematical Journal 44, no. 3, 275--313, 2014.

6. Sugiyama, Yuusuke; Yamamoto, Masakazu; Kato, Keiichi, Local and global solvability and blow up for the drift-diffusion equation with the fractional dissipation in the critical space, Journal of Differential Equations 258, no. 9, 2983--3010, 2015.

7. Sugiyama, Yuusuke, Degeneracy in finite time of 1D quasilinear wave equations, SIAM Journal on Mathematical Analysis 48, no. 2, 847--860, 2016.

8. Yamamoto, Masakazu; Sugiyama, Yuusuke, Asymptotic behavior of solutions to the drift-diffusion equation with critical dissipation, Annales Henri Poincaré 17, no. 6, 1331--1352, 2016.

9. Yamamoto, Masakazu; Sugiyama, Yuusuke, Asymptotic expansion of solutions to the drift-diffusion equation with fractional dissipation, Nonlinear Analysis 141, 57--87, 2016.

10. Sugiyama, Yuusuke, Degeneracy in finite time of 1D quasilinear wave equations. II., Evolution Equations and Control Theory 6, no. 4, 615--628, 2017.

11. Sugiyama, Yuusuke, Large time behavior of solutions to 1D quasilinear wave equations, RIMS Kôkyûroku Bessatsu B63, 115--125, 2017.

12. Sugiyama, Yuusuke, Singularity formation for the 1D compressible Euler equations with variable damping coefficient, Nonlinear Analysis 170, 70--87, 2018.

13. Lu, Yun-Guang; Sugiyama, Yuusuke, Existence and nonexistence theorems of global weak solutions to degenerate quasilinear wave equations for the elasticity, Applied Mathematics Letters 84, 118--123, 2018.

14. Yamamoto, Masakazu; Sugiyama, Yuusuke, Spatial-decay of solutions to the quasi-geostrophic equation with the critical and supercritical dissipation, Nonlinearity 32, no. 7, 2467--2480, 2019.

15. Yamamoto, Masakazu; Sugiyama, Yuusuke, Optimal estimates for far field asymptotics of solutions to the quasi-geostrophic equation, Proceedings of the American Mathematical Society 149, no. 3, 1099--1110, 2021.

16. Sugiyama, Yuusuke, Remark on global existence of solutions to the 1D compressible Euler equation with time-dependent damping, in Advanced Studies in Pure Mathematics 85, 379--389, 2021.

17. Sugiyama, Yuusuke; Yamamoto, Masakazu, Asymptotic stability of stationary solutions to the drift-diffusion model with the fractional dissipation, Journal of Evolution Equations 21, no. 2, 1383--1417, 2021.

18. Sugiyama, Yuusuke, Formation of singularities for a family of 1D quasilinear wave equations, Indiana University Mathematics Journal 71, no. 6, 2529--2549, 2022.

19. Sugiyama, Yuusuke, Local solvability for a quasilinear wave equation with the far field degeneracy: 1D case, Communications in Mathematical Sciences 21, no. 1, 219--237, 2023.

20. Hu, Yanbo; Sugiyama, Yuusuke, The classical solvability for a one-dimensional nonlinear thermoelasticity system with the far field degeneracy, Advances in Nonlinear Studies 24, no. 4, 857--879, 2024.

21. Sugiyama, Yuusuke, Global existence and blow-up for the 1D damped compressible Euler equations with time and space dependent perturbation, Nonlinear Analysis 250, Article ID 113658, 2025.

22. Hu, Yanbo; Sugiyama, Yuusuke, Well-posedness of the initial-boundary value problem for 1D degenerate quasilinear wave equations, Advances in Differential Equations 30, no. 3-4, 177--206, 2025.

23. Hu, Yanbo; Sugiyama, Yuusuke, Well-posedness of degenerate initial-boundary value problems to a hyperbolic-parabolic coupled system arising from nematic liquid crystals, Archive for Rational Mechanics and Analysis 249, no. 2, Paper No. 19, 2025.