Let U be a real n x n matrix whose entries uij are random variables, and let A and B be fixed n x n real symmetric matrices. Statisticians (e.g., see [OU]) have been interested in the distribution of the eigenvalues d l , . . . , O n of the matrix AUBUt, where denotes transpose. Of particular interest are the quantities tr((AU = C 0; for k = 1,2,. . . , since these determine the eigenvalues. Mo...

in this paper, a fundamentally new method, based on the denition, is introduced for numerical computation of eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices. some examples are provided to show the accuracy and reliability of the proposed method. it is shown that the proposed method gives other sequences than that of existing methods but they still are convergent to t...

In this paper has been studied the wave equation in some non-classic cases. In the  rst case boundary conditions are non-local and non-periodic. At that case the associated spectral problem is a self-adjoint problem and consequently the eigenvalues are real. But the second case the associated spectral problem is non-self-adjoint and consequently the eigenvalues are complex numbers,in which two ...

We introduce three universality classes of chiral random matrix ensembles with a nonzero chemical potential and real, complex or quaternion real matrix elements. In the thermodynamic limit we find that the distribution of the eigenvalues in the complex plane does not depend on the Dyson index, and is given by the solution proposed by Stephanov. For a finite number of degrees of freedom, N , we ...

We prove that the eigenvalues of a certain highly non-self-adjoint operator that arises in fluid mechanics correspond, up to scaling by a positive constant, to those of a self-adjoint operator with compact resolvent; hence there are infinitely many real eigenvalues which accumulate only at ±∞. We use this result to determine the asymptotic distribution of the eigenvalues and to compute some of ...

We study the spectrum of unbounded J-self-adjoint block operator matrices. In particular, we prove enclosures for the spectrum, provide a sufficient condition for the spectrum being real and derive variational principles for certain real eigenvalues even in the presence of non-real spectrum. The latter lead to lower and upper bounds and asymptotic estimates for eigenvalues. AMS Subject classifi...

Two issues concerning the construction of square matrices with prescribed singular values and eigenvalues are addressed. First, a necessary and sufficient condition for the existence of an n × n complex matrix with n given nonnegative numbers as singular values and m(≤ n) given complex numbers to be m of the eigenvalues is determined. This extends the classical result of Weyl and Horn treating ...

We consider the eigenvalues of the biharmonic operator subject to several homogeneous boundary conditions (Dirichlet, Neumann, Navier, Steklov). We show that simple eigenvalues and elementary symmetric functions of multiple eigenvalues are real analytic, and provide Hadamard-type formulas for the corresponding shape derivatives. After recalling the known results in shape optimization, we prove ...

Inequalities which bound the closed-loop eigenvalues in an LQ-optimal system are presented. It is shown that the eigenvalues are bounded by two half circles with radii r1 and r2 and center at 0, where = 0 is the imaginary axis, and that the imaginary parts of these eigenvalues are bounded from up and below by two lines parallel to the real axis.

Ky Fan’s result states that the real parts of the eigenvalues of an n × n complex matrix x are majorized by the eigenvalues of the Hermitian part of x. The converse was established by Amir-Moéz and Horn, and Mirsky, independently. We generalize the results in the context of complex semisimple Lie algebra. The real case is also discussed.