{"paper":{"title":"Comment on the paper \"Quasi-particle approach for lattice Hamiltonians with large coordination numbers\" by P. Navez, F. Queisser and R. Sch\\\"utzhold - J. Phys. A: Math. Theor. 47 225004 (2014)","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.str-el"],"primary_cat":"cond-mat.other","authors_text":"D. Psiachos","submitted_at":"2016-04-25T08:12:25Z","abstract_excerpt":"This comment regards a central aspect of the referred-to paper, the issue of convergence of the large coordination-number expansion. Perturbation expansions of expressions containing a large number of parameters are generally invalid due to the non-analyticity of the expanded expressions. I refer to recent work where these issues are analyzed and discussed in detail in relation to a benchmark example of a cluster model. As discussed therein, methods which are uncontrollable and for which their convergence is not foreseeable are not only useless but can mislead, particularly if models derived f"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1604.07158","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}