title: Asymptotic response of observables from divergent weak-coupling expansions: a fractional-calculus-assisted Padé technique.
abstract: Appropriate constructions of Padé approximants are believed to provide reasonable estimates of the asymptotic (large-coupling) amplitude and exponent of an observable, given its weak-coupling expansion to some desired order. In many instances, however, sequences of such approximants are seen to converge very poorly. We outline here a strategy that exploits the idea of fractional calculus to considerably improve the convergence behavior. Pilot calculations on the ground-state perturbative energy series of quartic, sextic, and octic anharmonic oscillators reveal clearly the worth of our endeavor.
authors.affiliation: Department of Chemistry, University of Calcutta, Kolkata, India. pcsdhatt@gmail.com
authors.forename: Sharmistha
authors.initials: S
authors.lastname: Dhatt
authors.forename: Kamal
authors.initials: K
authors.lastname: Bhattacharyya