--- _id: '8044' abstract: - lang: eng text: Many questions concerning models in quantum mechanics require a detailed analysis of the spectrum of the corresponding Hamiltonian, a linear operator on a suitable Hilbert space. Of particular relevance for an understanding of the low-temperature properties of a system is the structure of the excitation spectrum, which is the part of the spectrum close to the spectral bottom. We present recent progress on this question for bosonic many-body quantum systems with weak two-body interactions. Such system are currently of great interest, due to their experimental realization in ultra-cold atomic gases. We investigate the accuracy of the Bogoliubov approximations, which predicts that the low-energy spectrum is made up of sums of elementary excitations, with linear dispersion law at low momentum. The latter property is crucial for the superfluid behavior the system. article_processing_charge: No author: - first_name: Robert full_name: Seiringer, Robert id: 4AFD0470-F248-11E8-B48F-1D18A9856A87 last_name: Seiringer orcid: 0000-0002-6781-0521 citation: ama: 'Seiringer R. Structure of the excitation spectrum for many-body quantum systems. In: Proceeding of the International Congress of Mathematicans. Vol 3. International Congress of Mathematicians; 2014:1175-1194.' apa: 'Seiringer, R. (2014). Structure of the excitation spectrum for many-body quantum systems. In Proceeding of the International Congress of Mathematicans (Vol. 3, pp. 1175–1194). Seoul, South Korea: International Congress of Mathematicians.' chicago: Seiringer, Robert. “Structure of the Excitation Spectrum for Many-Body Quantum Systems.” In Proceeding of the International Congress of Mathematicans, 3:1175–94. International Congress of Mathematicians, 2014. ieee: R. Seiringer, “Structure of the excitation spectrum for many-body quantum systems,” in Proceeding of the International Congress of Mathematicans, Seoul, South Korea, 2014, vol. 3, pp. 1175–1194. ista: 'Seiringer R. 2014. Structure of the excitation spectrum for many-body quantum systems. Proceeding of the International Congress of Mathematicans. ICM: International Congress of Mathematicans vol. 3, 1175–1194.' mla: Seiringer, Robert. “Structure of the Excitation Spectrum for Many-Body Quantum Systems.” Proceeding of the International Congress of Mathematicans, vol. 3, International Congress of Mathematicians, 2014, pp. 1175–94. short: R. Seiringer, in:, Proceeding of the International Congress of Mathematicans, International Congress of Mathematicians, 2014, pp. 1175–1194. conference: end_date: 2014-08-21 location: Seoul, South Korea name: 'ICM: International Congress of Mathematicans' start_date: 2014-08-13 date_created: 2020-06-29T07:59:35Z date_published: 2014-08-01T00:00:00Z date_updated: 2023-10-17T11:12:33Z day: '01' department: - _id: RoSe intvolume: ' 3' language: - iso: eng main_file_link: - open_access: '1' url: http://www.icm2014.org/en/vod/proceedings.html month: '08' oa: 1 oa_version: Published Version page: 1175-1194 publication: Proceeding of the International Congress of Mathematicans publication_identifier: isbn: - '9788961058063' publication_status: published publisher: International Congress of Mathematicians quality_controlled: '1' scopus_import: '1' status: public title: Structure of the excitation spectrum for many-body quantum systems type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 3 year: '2014' ...