Calculation of Dynamical Response Functions Using a Bound-State Method

Niels r. Walet, Jagjit Singh, Johannes Kirscher, Michael c. Birse, Harald w. Grießhammer, Judith a. Mcgovern

Research output: Contribution to journalArticlepeer-review


We investigate a method to extract response functions (dynamical polarisabilities) directly from a bound-state approach applied to calculations of perturbation-induced reactions. The use of a square-integrable basis leads to a response in the form of a sum of δ functions. We integrate this over energy and fit a smooth function to the resulting stepwise-continuous one. Its derivative gives the final approximation to the physical response function. We show that the method reproduces analytical results where known, and analyse the details for a variety of models. We apply it to some simple models, using the stochastic variational method as the numerical method. Albeit we find that this approach, and other numerical techniques, have some difficulties with the threshold behavior in coupled-channel problems with multiple thresholds, its stochastic nature allows us to extract robust results even for such cases.
Original languageEnglish
JournalFew-Body Systems
Issue number3
Publication statusPublished - 30 Jun 2023


Dive into the research topics of 'Calculation of Dynamical Response Functions Using a Bound-State Method'. Together they form a unique fingerprint.

Cite this