5 papers
Index theory for non-compact quantum graphs
Daniele Garrisi, Alessandro Portaluri, Li Wu
We develop an index theory for variational problems on noncompact quantum graphs. The main results are a spectral flow formula, relating the net change of eigenvalues to the Maslov…
Non-minimality and instability of brake orbits for natural Lagrangians on Riemannian manifolds
Luca Asselle, Xijun Hu, Alessandro Portaluri +1
We investigate minimality and stability of periodic brake orbits in natural Lagrangian systems on smooth Riemannian manifolds. We prove that every non-constant periodic brake orbit…
Index theory for singular Lagrangian systems and Bessel-type differential operators
Xijun Hu, Alessandro Portaluri, Li Wu
The aim of the present manuscript is to develop an index theory for singular Lagrangian systems, with a particular focus on the important class of singular operators given by Besse…
The fibered rotation number for ergodic symplectic cocycles and its applications: I. Gap Labelling Theorem
Xianzhe Li, Li Wu
Let be an ergodic topological dynamical system. The fibered rotation number for cocycles in , acting on $ Î\times \mathbb{R}\ma…
A formula of local Maslov index and applications
Li Wu, Chaofeng Zhu
In this paper, we explicitly express the local Maslov index by a Maslov index in finite dimensional case without symplectic reduction. Then we calculate the Maslov index for the pa…