Consider a power series f ∈ R[[z]], which is obtained by a precise mathematical construction. For instance, f might be the solution to some differential or functional initial value problem or the diagonal of the solution to a partial differential equation. In cases when no suitable method is beforehand for determining the asymptotics of the coefficients fn, but when many such coefficients can b...

Local expansion exponents for nonequilibrium dynamical systems, described by partial differential equations, are introduced. These exponents show whether the system phase volume expands, contracts, or is conserved in time. The ways of calculating the exponents are discussed. The principle of minimal expansion provides the basis for treating the problem of pattern selection. The exponents are al...

A new asymptotic expansion method is developed to separate the WheelerDeWitt equation into the time-dependent Schrödinger equation for a matter field and the Einstein-Hamilton-Jacobi equation for the gravitational field including the quantum back-reaction of the matter field. In particular, the nonadiabatic basis of the generalized invariant for the matter field Hamiltonian separates the Wheele...

Takemura and Sheena (2002) derived the asymptotic joint distribution of the eigenvalues and the eigenvectors of Wishart matrix when the population eigenvalues become infinitely dispersed. They also showed necessary conditions for an estimator of the population covariance matrix to be minimax for typical loss functions by calculating the asymptotic risk of the estimator. In this paper, we furthe...

We consider a particle undergoing diffusion with stochastic resetting in bounded domain for . The is perforated by set of partially absorbing spherical targets within which the may be absorbed at rate Each target assumed to much smaller than , allows us use asymptotic and Green’s function methods solve equation Laplace space. In particular, we construct an inner solution interior local exterior...

Product integration methods for Cauchy principal value integrals based on piecewise Lagrangian interpolation are studied. I t is shown that for this class of quadrature methods the truncation error has an asymptotic expansion in integer powers of the step-size, and that a method with an asymptotic expansion in even powers of the step-size does not exist. The relative merits of a quadrature meth...

We present a method for the numerical quadrature of highly oscillatory integrals with stationary points. We begin with the derivation of a new asymptotic expansion, which has the property that the accuracy improves as the frequency of oscillations increases. This asymptotic expansion is closely related to the method of stationary phase, but presented in a way that allows the derivation of an al...

We study the initial value problem of a singularly perturbed first order ordinary differential equation in case that the degenerate equation has a double root. We construct the formal asymptotic expansion of the solution such that the boundary layer functions decay exponentially. This requires a modification of the standard procedure. The asymptotic solution will be used to construct lower and ...

We derive the complete asymptotic expansion in terms of powers of N for the Riesz s-energy of N equally spaced points on the unit circle as N →∞. For s ≥ −2, such points form optimal energy N -point configurations with respect to the Riesz potential 1/r, s 6= 0, where r is the Euclidean distance between points. By analytic continuation we deduce the expansion for all complex values of s. The Ri...

A modification of standard Poincaré asymptotic expansions for functions defined by means of Laplace transforms is analyzed. This modification is based on an alternative power series expansion of the integrand, and the convergence properties are seen to be superior to those of the original asymptotic series. The resulting modified asymptotic expansion involves confluent hypergeometric functions ...