3 citations · 9 across the 15 of their papers we have counts for
16 papers
Linear instability of periodic orbits of free period Lagrangian systems
Alessandro Portaluri, Li Wu, Ran Yang
In this paper we provide a sufficient condition for the linear instability of a periodic orbit for a free period Lagrangian system on a Riemannian manifold. The main result establi…
Spectral stability, spectral flow and circular relative equilibria for the Newtonian -body problem
Luca Asselle, Alessandro Portaluri, Li Wu
For the Newtonian (gravitational) -body problem in the Euclidean -dimensional space, , the simplest possible periodic solutions are provided by circular relative equi…
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…
Morse index theorem for heteroclinic, homoclinic and halfclinic orbits of Lagrangian systems
Xijun Hu, Alessandro Portaluri, Li Wu +1
The purpose of this paper is to prove a new, more general version of the Morse index theorem for heteroclinic, homoclinic, and half-clinic solutions in general Lagrangian systems.…
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…
Weil-Petersson Teichmüller space III: dependence of Riemann mappings for Weil-Petersson curves
Yuliang Shen, Li Wu
The primary purpose of the paper is to study how a Riemann mapping depends on the corresponding Jordan curve. We are mainly concerned with those Jordan curves in the Weil-Petersson…
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…
Decomposition of Spectral flow and Bott-type Iteration Formula
Xijun Hu, Li Wu
Let be a continuous path of Fredhom operators, we first prove that the spectral flow is cogredient invariant. Based on this property, we give a decomposition form…
Singularity of the -th eigenvalue of high dimensional Sturm-Liouville problems
Xijun Hu, Lei Liu, Li Wu +1
It is natural to consider continuous dependence of the -th eigenvalue on -dimensional () Sturm-Liouville problems after the results on -dimensional case by Kong, W…
The Hörmander index in the finite-dimensional case
Yuting Zhou, Li Wu, Chaofeng Zhu
In this paper, we calculate Hörmander index in the finite-dimensional case. Then we use the result to give some iteration inequalities, and prove almost existence of mean indices f…
Morse Index Theorem of Lagrangian Systems and Stability of Brake Orbit
Xijun Hu, Li Wu, Ran Yang
In this paper, we prove Morse index theorem of Lagrangian system with any self-adjoint boundary conditions. Based on it, we give some nontrivial estimation on the difference of Mor…
Multiplicity of closed characteristics on -symmetric compact convex hypersurfaces in
Lei Liu, Li Wu
There is a long standing conjecture that there are at least closed characteristics for any compact convex hypersurface in , and the symmetric case, i.e. $Σ…
Iteration formulae of the Maslov-type index theory in weak symplectic Hilbert spaces
Li Wu, Chaofeng Zhu
In this paper, we prove a splitting formula for the Maslov-type indices of symplectic paths induced by the splitting of the nullity in weak symplectic Hilbert space. Then we give a…