Manifold decompositions and indices of Schr\"odinger operators
Manifold decompositions and indices of Schr\"odinger operators
复制标题
Schr"odinger算子的流形分解和指数
DOI:
10.1512/iumj.2017.66.6129
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发表时间:
2015
期刊:
影响因子:
--
通讯作者:
J. Marzuola
中科院分区:
文献类型:
--
作者:
G. Cox;C. Jones;J. Marzuola
The Maslov index is used to compute the spectra of different boundary value problems for Schr\"{o}dinger operators on compact manifolds. The main result is a spectral decomposition formula for a manifold $M$ divided into components $\Omega_1$ and $\Omega_2$ by a separating hypersurface $\Sigma$. A homotopy argument relates the spectrum of a second-order elliptic operator on $M$ to its Dirichlet and Neumann spectra on $\Omega_1$ and $\Omega_2$, with the difference given by the Maslov index of a path of Lagrangian subspaces. This Maslov index can be expressed in terms of the Morse indices of the Dirichlet-to-Neumann maps on $\Sigma$. Applications are given to doubling constructions, periodic boundary conditions and the counting of nodal domains. In particular, a new proof of Courant's nodal domain theorem is given, with an explicit formula for the nodal deficiency.