Continuation methods are a well-known technique for computing several stationary solutions of problems involving one or more physical parameters. In order to determine whether a stationary solution is stable, and to detect the bifurcation points of the problem, one has to compute the rightmost eigenvalues of a related, generalized eigenvalue problem. The recently developed Jacobi-Davidson QZ me...

It is important to seek for more explicit exact solutions of nonlinear partial differential equations (NLPDEs) in mathematical physics. With the help of symbolic computation software like Maple or Mathematica, much work has been focused on the various extensions and applications of the known methods to construct exact solutions of NLPDEs. Mathematical modelling of physical systems often leads t...

The Jacobi-Davidson subspace iteration method ooers possibilities for solving a variety of eigen-problems. In practice one has to apply restarts because of memory limitations, in order to restrict computational overhead, and also if one wants to compute several eigenvalues. In general, restarting has negative eeects on the convergence of subspace methods. We will show how eeective restarts can ...

Let p, q be distinct primes satisfying gcd(p−1, q−1) = d and letDi, i = 0, 1, · · · , d−1, be Whiteman’s generalized cyclotomic classes with Z∗ pq = ∪ d−1 i=0Di. In this paper, we give the values of Gauss periods based on the generalized cyclotomic sets D∗ 0 = ∑ d 2 −1 i=0 D2i and D ∗ 1 = ∑ d 2 −1 i=0 D2i+1. As an application, we determine a lower bound on the 2-adic complexity of modified Jaco...

We prove matching direct and inverse theorems for (algebraic) polynomial approximation with doubling weights w having finitely many zeros and singularities (i.e., points where w becomes infinite) on an interval and not too “rapidly changing” away from these zeros and singularities. This class of doubling weights is rather wide and, in particular, includes the classical Jacobi weights, generaliz...

This paper provides a direct equivalence proof for minimax solutions of A.I. Subbotin and generalized weak solutions in the sense of idempotent analysis. It is shown that the Hamilton-Jacobi equation Vt+H(t, x,DxV ) = 0 (with the Hamiltonian H(t, x, s) concave in s), considered in the context of minimax generalized solutions, is linear w.r.t. ⊕ = min and ̄ = +. This leads to a representation fo...

The Jacobi polynomials induce a translation operator on function spaces on the interval [−1, 1]. For any homogeneous Banach space B w.r.t. this translation, we can study the according little and big Lipschitz spaces, lipB(λ) and LipB(λ), respectively. The big Lipschitz spaces are not homogeneous themselves. Therefore we introduce semihomogeneous Banach spaces w.r.t. Jacobi translation, of which...

We study a stepwise algorithm for solving the indefinite truncated moment problem and obtain the factorization of the matrix describing the solution of this problem into elementary factors. We consider the generalized Jacobi matrix corresponding to Magnus’ continuous P -fraction that appears in this algorithm and the polynomials of the first and second kind that are solutions of the correspondi...

In this paper, we establish real Paley-Wiener theorems for the Dunkl transform on IR d. More precisely, we characterize the functions in the Schwartz space S(IR d) and in L 2 k (IR d) whose Dunkl transform has bounded, unbounded, convex and nonconvex support. 1 Introduction In the last few years there has been a great interest to real Paley-Wiener theorems for certain integral transforms, see [...