{"article_type":"original","publisher":"Wiley","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","external_id":{"arxiv":["2409.17914"]},"date_created":"2026-03-22T23:04:33Z","year":"2026","doi":"10.1002/cpa.70040","status":"public","author":[{"last_name":"Giacomelli","first_name":"Emanuela L.","full_name":"Giacomelli, Emanuela L."},{"full_name":"Hainzl, Christian","first_name":"Christian","last_name":"Hainzl"},{"last_name":"Nam","first_name":"Phan Thành","full_name":"Nam, Phan Thành"},{"full_name":"Seiringer, Robert","first_name":"Robert","last_name":"Seiringer","orcid":"0000-0002-6781-0521","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87"}],"title":"The Huang–Yang formula for the low-density Fermi gas: Upper bound","publication_identifier":{"issn":["0010-3640"],"eissn":["1097-0312"]},"date_published":"2026-03-13T00:00:00Z","scopus_import":"1","citation":{"ista":"Giacomelli EL, Hainzl C, Nam PT, Seiringer R. 2026. The Huang–Yang formula for the low-density Fermi gas: Upper bound. Communications on Pure and Applied Mathematics.","short":"E.L. Giacomelli, C. Hainzl, P.T. Nam, R. Seiringer, Communications on Pure and Applied Mathematics (2026).","ama":"Giacomelli EL, Hainzl C, Nam PT, Seiringer R. The Huang–Yang formula for the low-density Fermi gas: Upper bound. <i>Communications on Pure and Applied Mathematics</i>. 2026. doi:<a href=\"https://doi.org/10.1002/cpa.70040\">10.1002/cpa.70040</a>","chicago":"Giacomelli, Emanuela L., Christian Hainzl, Phan Thành Nam, and Robert Seiringer. “The Huang–Yang Formula for the Low-Density Fermi Gas: Upper Bound.” <i>Communications on Pure and Applied Mathematics</i>. Wiley, 2026. <a href=\"https://doi.org/10.1002/cpa.70040\">https://doi.org/10.1002/cpa.70040</a>.","ieee":"E. L. Giacomelli, C. Hainzl, P. T. Nam, and R. Seiringer, “The Huang–Yang formula for the low-density Fermi gas: Upper bound,” <i>Communications on Pure and Applied Mathematics</i>. Wiley, 2026.","mla":"Giacomelli, Emanuela L., et al. “The Huang–Yang Formula for the Low-Density Fermi Gas: Upper Bound.” <i>Communications on Pure and Applied Mathematics</i>, Wiley, 2026, doi:<a href=\"https://doi.org/10.1002/cpa.70040\">10.1002/cpa.70040</a>.","apa":"Giacomelli, E. L., Hainzl, C., Nam, P. T., &#38; Seiringer, R. (2026). The Huang–Yang formula for the low-density Fermi gas: Upper bound. <i>Communications on Pure and Applied Mathematics</i>. Wiley. <a href=\"https://doi.org/10.1002/cpa.70040\">https://doi.org/10.1002/cpa.70040</a>"},"OA_place":"publisher","publication":"Communications on Pure and Applied Mathematics","department":[{"_id":"RoSe"}],"abstract":[{"text":"We study the ground state energy of a gas of spin 1/2 fermions with repulsive short-range interactions. We derive an upper bound that agrees, at low density e, with the Huang–Yang conjecture. The latter captures the first three terms in an asymptotic low-density expansion, and in particular the Huang–Yang correction term of order e^7/3. Our trial state is constructed using an adaptation of the bosonic Bogoliubov theory to the Fermi system, where the correlation structure of fermionic particles is incorporated by quasi-bosonic Bogoliubov transformations. In the latter, it is important to consider a modified zero-energy scattering equation that takes into account the presence of the Fermi sea, in the spirit of the Bethe–Goldstone equation.","lang":"eng"}],"main_file_link":[{"url":"https://doi.org/10.1002/cpa.70040","open_access":"1"}],"language":[{"iso":"eng"}],"article_processing_charge":"Yes (via OA deal)","date_updated":"2026-03-23T13:32:14Z","publication_status":"epub_ahead","oa":1,"type":"journal_article","oa_version":"Published Version","arxiv":1,"_id":"21472","acknowledgement":"We thank the referees for valuable remarks. This work was partially funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via the TRR 352 – Project-ID 470903074. PTN was partially supported by the European Research Council via the ERC Consolidator Grant RAMBAS – Project-Nr. 10104424.\r\nOpen access publishing facilitated by Università degli Studi di Milano, as part of the Wiley - CRUI-CARE agreement.","OA_type":"hybrid","month":"03","day":"13","quality_controlled":"1"}