Inverse spectral problem for analytic plane domains II: $\Z_2$-symmetric domains

5×5对称非负逆特征值问题的一个新不可能区域

A New Impossibility Region for the $5\times5$ Symmetric Nonnegative Inverse Eigenvalue Problem

本文针对5×5对称非负逆特征值问题，提出新的低迹不可能区域，通过对角移位转化问题、简化互补交换矩阵为加权五元环，利用其特征多项式与谱恒等式推导矛盾，补充了该问题的理论边界。

On the Moore-Penrose pseudo-inversion of block symmetric matrices and its application in the graph theory

The purpose of this paper is to analyze the Moore-Penrose pseudo-inversion of symmetric real matrices with application in the graph theory. We introduce a novel concept of positively and negatively pseudo-inverse matrices and graphs. We also give sufficient conditions on the elements of a block symmetric matrix yielding an explicit form of its Moore-Penrose pseudo-inversion. Using the explicit form of the pseudo-inverse matrix we can construct pseudo-inverse graphs for a class of graphs which are constructed from the original graph by adding pendent vertices or pendant paths.

Recovering Differential Operators with Nonseparated Boundary Conditions in the Central Symmetric Case

Inverse spectral problems for Sturm-Liouville operators on a finite interval with non-separated boundary conditions are studied in the central symmetric case, when the potential is symmetric with respect to the middle of the interval. We discuss statements of the problems, provide algorithms for their solutions along with necessary and sufficient conditions for the solvability of the inverse problems considered.

Inverse Sturm-Liouville problem with analytical functions in the boundary condition

The inverse spectral problem is studied for the Sturm-Liouville operator with a complex-valued potential and arbitrary entire functions in one of the boundary conditions. We obtain necessary and sufficient conditions for uniqueness, and develop a constructive algorithm for the inverse problem solution. The main results are applied to the Hochstadt-Lieberman half-inverse problem. As an auxiliary proposition, we prove local solvability and stability for the inverse Sturm-Liouville problem by the Cauchy data in the non-self-adjoint case.

Inverse problems for symmetric doubly stochastic matrices whose Suleĭmanova spectra are bounded below by 1/2

A new sufficient condition for a list of real numbers to be the spectrum of a symmetric doubly stochastic matrix is presented; this is a contribution to the classical spectral inverse problem for symmetric doubly stochastic matrices that is still open in its full generality. It is proved that whenever $λ_2, \ldots, λ_n$ are non-positive real numbers with $1 + λ_2 + \ldots + λ_n \geqslant 1/2$, then there exists a symmetric, doubly stochastic matrix whose spectrum is precisely $(1, λ_2, \ldots, λ_n)$. We point out that this criterion is incomparable to the classical sufficient conditions due to…

The inverse resonance problem for $\Z_2$-symmetric analytic obstacles in the plane

We prove that a two-component mirror-symmetric analytic obstacle in the plane is determined by its resonance poles among such obstacles. The proof is essentially the same as in the interior case (part II of the series). A so-called interior/exterior duality formula is used to simplify the proof. A fair amount of exposition is included for the sake of completeness.

完备黎曼流形上对称双曲偏微分算子的反问题

An Inverse Problem for symmetric hyperbolic Partial Differential Operators on Complete Riemannian Manifolds

本文研究完备黎曼流形上对称双曲偏微分算子的反问题，通过改进边界控制方法（BC-method），从局部源到解映射唯一恢复流形及低阶项。

Analyticity and uniform stability in the inverse spectral problem for Dirac operators

We prove that the inverse spectral mapping reconstructing the square integrable potentials on [0,1] of Dirac operators in the AKNS form from their spectral data (two spectra or one spectrum and the corresponding norming constants) is analytic and uniformly stable in a certain sense.

Centrally symmetric analytic plane domains are spectrally determined in this class

We prove that, under some generic non-degeneracy assumptions, real analytic, centrally symmetric plane domains are determined by their Dirichlet (resp. Neumann) spectra. We prove that the conditions are open-dense for real analytic convex domains. The proof is parallel to the proof that up/down symmetric domains are spectrally determined. One step is to use a Maslov index calculation to show that the second derivative of the defining function of a centrally symmetric domain at the endpoints of a bouncing ball orbit is a spectral invariant. This is also true for up/down symmetric domains, remov…

Analyticity and uniform stability of the inverse singular Sturm--Liouville spectral problem

We prove that the potential of a Sturm--Liouville operator depends analytically and Lipschitz continuously on the spectral data (two spectra or one spectrum and the corresponding norming constants). We treat the class of operators with real-valued distributional potentials in the Sobolev class W^{s-1}_2(0,1), s\in[0,1].

An algorithm for constructing doubly stochastic matrices for the inverse eigenvalue problem

In this note, we present an algorithm that yields many new methods for constructing doubly stochastic and symmetric doubly stochastic matrices for the inverse eigenvalue problem. In addition, we introduce new open problems in this area that lay the ground for future work

Analytic torsion and L^2-torsion of compact locally symmetric manifolds

In this paper we study the analytic torsion and the $L^2$-torsion of compact locally symmetric manifolds. We consider the analytic torsion with respect to representations of the fundamental group which are obtained by restriction of irreducible representations of the group of isometries of the underlying symmetric space. The main purpose is to study the asymptotic behavior of the analytic torsion with respect to sequences of representations associated to rays of highest weights.