New Periodic Solutions of Singular Hamiltonian Systems with Fixed Energies

By using the variational minimizing method with a special constraint and the direct variational minimizing method without constraint, we study second order Hamiltonian systems with a singular potential $V\in C^2(R^n\backslash O,R)$ and $V\in C^1(R^2\backslash O,R)$ which may have an unbounded potential well, and prove the existence of non-trivial periodic solutions with a prescribed energy. Our results can be regarded as some complements of the well-known Theorems of Benci-Gluck-Ziller-Hayashi and Ambrosetti-Coti Zelati and so on

Experimental study on wave attenuation due to flexible intertidal vegetation（柔軟な干潟上植生による波浪減衰に関する実験的研究）

東京海洋大学修士学位論文 2019(2020年3月) 海洋資源環境学 修士 第3308号指導教員: 岡安章夫全文公表年月日: 2020-06-22東京海洋大学201

A Note on Homoclinic Orbits for Second Order Hamiltonian Systems

In this paper, we study the existence for the homoclinic orbits for the second order Hamiltonian systems. Under suitable conditions on the potential $V$, we apply the direct method of variations and the Fourier analysis to prove the existence of homoclinc orbits