English

In-medium similarity renormalization group for a pairing-plus-particle-hole model

Nuclear Theory 2025-08-13 v1

Abstract

We benchmark two implementations of the in-medium similarity renormalization group (IMSRG) method, IMSRG(2) and IMSRG(2*), for the low-lying states of a pairing-plus-particle-hole model with varying numbers of fermions. In IMSRG(2), all operators are truncated up to the normal-ordered two-body terms, whereas IMSRG(2*) includes an additional term to partially account for higher-body contributions. The results are compared against exact solutions. We find that IMSRG(2*) consistently outperforms IMSRG(2) for both ground and excited states, although achieving convergence for excited states remains more challenging in strongly correlated systems than for the ground state.

Keywords

Cite

@article{arxiv.2508.08595,
  title  = {In-medium similarity renormalization group for a pairing-plus-particle-hole model},
  author = {L. H. Chen and Y. G. Yao and B. C. He},
  journal= {arXiv preprint arXiv:2508.08595},
  year   = {2025}
}

Comments

7 pages, 10 figures

R2 v1 2026-07-01T04:45:29.522Z