The ratio of eigenvalues of the Dirichlet eigenvalue problem for equations with one-dimensional -Laplacian.
The spectra of general differential operators in the direct sum spaces
In this paper, the general ordinary quasi-differential expression of -th order with complex coefficients and its formal adjoint on any finite number of intervals , , are considered in the setting of the direct sums of -spaces of functions defined on each of the separate intervals, and a number of results concerning the location of the point spectra and the regularity fields of general differential operators generated by such expressions are obtained. Some of these are extensions or generalizations...
Théorèmes taubériens et théorie spectrale
Théorie de Galois -adique
Three methods for the study of semilinear equations at resonance
Three methods for the study of the solvability of semilinear equations with noninvertible linear parts are compared: the alternative method, the continuation method of Mawhin and a new perturbation method [22]-[27]. Some extension of the last method and applications to differential equations in Banach spaces are presented.
Topological -adic vector spaces and index theory
Trace Formulas of Gelfand--levitan Type
Über die Zerlegungen von linearen homogenen Differentialoperatoren
Über die Zerlegungen von linearen homogenen Differentialoperatoren in Operatoren erster Ordnung
Über maximale LP-Regularität für Differentialgleichungen in Banach- und Hilbert-Räumen.
Über Störungen kanonischer Differentialgleichungen mit operatorwertigen Koeffizienten und definisierbarem Monodromieoperator.
Uniform convergence of the spectral expansion for a differential operator with periodic matrix coefficients.
Universality of derivative and antiderivative operators with holomorphic coefficients
We prove some conditions on a sequence of functions and on a complex domain for the existence of universal functions with respect to sequences of certain derivative and antiderivative operators related to them. Conditions for the equicontinuity of those families of operators are also studied. The conditions depend upon the "size" of the domain and functions. Some earlier results about multiplicative complex sequences are extended.
Vector spaces over function fields. Vector spaces over analytic function fields being associated to ordinary differential equations.
Vectors of uniqueness for id/dx
Verteilung der Eigenwerte für eine Klasse von Integraloperatoren in L2 (a, b).
Weak formulation of singular differential expressions in spaces of functions with minimal derivatives.
Weighted estimates for differential operators with operator-valued coefficients
Weighted inequalities and spectral problems.
Алгебраико-дифферециальные преобразования линейных дифференциальных операторов любого порядка и их спектральные свойства, применимые в обратной задаче