3 citations · 3 across the 6 of their papers we have counts for
12 papers
Mean index for non-periodic orbits in Hamiltonian systems
Xijun Hu, Li Wu
In this paper, we define mean index for non-periodic orbits in Hamiltonian systems and study its properties. In general, the mean index is an interval in R which is uniformly conti…
Spectral flow, Brouwer degree and Hill's determinant formula
Alessandro Portaluri, Li Wu
In 2005 a new topological invariant defined in terms of the Brouwer degree of a determinant map, was introduced by Musso, Pejsachowicz and the first name author for counting the co…
Sturm theory with applications in geometry and classical mechanics
Vivina L. Barutello, Daniel Offin, Alessandro Portaluri +1
Classical Sturm non-oscillation and comparison theorems as well as the Sturm theorem on zeros for solutions of second order differential equations have a natural symplectic version…
Poincar{é} and logarithmic sobolev inequalities for nearly radial measures
Patrick Cattiaux, Arnaud Guillin, Liming Wu
If Poincar{é} inequality has been studied by Bobkov for radial measures, few is known about the logarithmic Sobolev inequalty in the radial case. We try to fill this gap here using…
Linear instability for periodic orbits of non-autonomous Lagrangian systems
Alessandro Portaluri, Li Wu, Ran Yang
Inspired by the classical Poincaré criterion about the instability of orientation preserving minimizing closed geodesics on surfaces, we investigate the relation intertwining the i…
On the -th Eigenvalue of Sturm-Liouville Problem and the Maslov Index
Xijun Hu, Lei Liu, Li Wu +1
In the previous papers \cite{HLWZ,KWZ}, the jump phenomena of the -th eigenvalue were completely characterized for Sturm-Liouville problems. In this paper, we show that the jump…