{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T13:45:47Z","timestamp":1761745547902,"version":"build-2065373602"},"reference-count":39,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,11,10]],"date-time":"2021-11-10T00:00:00Z","timestamp":1636502400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Finite quantum many fermion systems are essential for our current understanding of Nature. They are at the core of molecular, atomic, and nuclear physics. In recent years, the application of information and complexity measures to the study of diverse types of many-fermion systems has opened a line of research that elucidates new aspects of the structure and behavior of this class of physical systems. In this work we explore the main features of information and information-based complexity indicators in exactly soluble many-fermion models of the Lipkin kind. Models of this kind have been extremely useful in shedding light on the intricacies of quantum many body physics. Models of the Lipkin kind play, for finite systems, a role similar to the one played by the celebrated Hubbard model of solid state physics. We consider two many fermion systems and show how their differences can be best appreciated by recourse to information theoretic tools. We appeal to information measures as tools to compare the structural details of different fermion systems. We will discover that few fermion systems are endowed by a much larger complexity-degree than many fermion ones. The same happens with the coupling-constants strengths. Complexity augments as they decrease, without reaching zero. Also, the behavior of the two lowest lying energy states are crucial in evaluating the system\u2019s complexity.<\/jats:p>","DOI":"10.3390\/e23111488","type":"journal-article","created":{"date-parts":[[2021,11,10]],"date-time":"2021-11-10T09:19:21Z","timestamp":1636535961000},"page":"1488","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Information-Theoretic Features of Many Fermion Systems: An Exploration Based on Exactly Solvable Models"],"prefix":"10.3390","volume":"23","author":[{"given":"Angel Ricardo","family":"Plastino","sequence":"first","affiliation":[{"name":"CeBio\u2014Departamento de Ciencias B\u00e1sicas, Universidad Nacional del Noroeste de la Prov. de Buenos Aires, CONICET, Junin 1988, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Diana","family":"Monteoliva","sequence":"additional","affiliation":[{"name":"UNLP\u2014Comisi\u00f3n de Investigaciones Cient\u00edficas Provincia de Buenos Aires La Plata, La Plata 1900, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5934-2783","authenticated-orcid":false,"given":"Angelo","family":"Plastino","sequence":"additional","affiliation":[{"name":"Instituto de F\u00edsica La Plata\u2014CCT-CONICET, Universidad Nacional de La Plata, C.C. 727, La Plata 1900, Argentina"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2150092","DOI":"10.1142\/S0217979221500922","article-title":"Statistical odd-even staggering in few fermions systems","volume":"35","author":"Pennini","year":"2021","journal-title":"Int. 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