{"title":"中子星合并中相对论性npeμ物质的体粘度","authors":"M. Alford, A. Harutyunyan, A. Sedrakian","doi":"10.3390/particles5030029","DOIUrl":null,"url":null,"abstract":"We discuss the bulk viscosity of hot and dense npeμ matter arising from weak-interaction direct Urca processes. We consider two regimes of interest: (a) the neutrino-transparent regime with T≤Ttr (Ttr≃5÷10 MeV is the neutrino-trapping temperature); and (b) the neutrino-trapped regime with T≥Ttr. Nuclear matter is modeled in relativistic density functional approach with density-dependent parametrization DDME2. The maximum of the bulk viscosity is achieved at temperatures T≃5÷6 MeV in the neutrino-transparent regime, then it drops rapidly at higher temperatures where neutrino-trapping occurs. As an astrophysical application, we estimate the damping timescales of density oscillations by the bulk viscosity in neutron star mergers and find that, e.g., at the oscillation frequency f=10 kHz, the damping will be very efficient at temperatures 4≤T≤7 MeV where the bulk viscosity might affect the evolution of the post-merger object.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"89 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"7","resultStr":"{\"title\":\"Bulk Viscosity of Relativistic npeμ Matter in Neutron-Star Mergers\",\"authors\":\"M. Alford, A. Harutyunyan, A. Sedrakian\",\"doi\":\"10.3390/particles5030029\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We discuss the bulk viscosity of hot and dense npeμ matter arising from weak-interaction direct Urca processes. We consider two regimes of interest: (a) the neutrino-transparent regime with T≤Ttr (Ttr≃5÷10 MeV is the neutrino-trapping temperature); and (b) the neutrino-trapped regime with T≥Ttr. Nuclear matter is modeled in relativistic density functional approach with density-dependent parametrization DDME2. The maximum of the bulk viscosity is achieved at temperatures T≃5÷6 MeV in the neutrino-transparent regime, then it drops rapidly at higher temperatures where neutrino-trapping occurs. As an astrophysical application, we estimate the damping timescales of density oscillations by the bulk viscosity in neutron star mergers and find that, e.g., at the oscillation frequency f=10 kHz, the damping will be very efficient at temperatures 4≤T≤7 MeV where the bulk viscosity might affect the evolution of the post-merger object.\",\"PeriodicalId\":75932,\"journal\":{\"name\":\"Inhaled particles\",\"volume\":\"89 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-09-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"7\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Inhaled particles\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3390/particles5030029\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inhaled particles","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/particles5030029","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Bulk Viscosity of Relativistic npeμ Matter in Neutron-Star Mergers
We discuss the bulk viscosity of hot and dense npeμ matter arising from weak-interaction direct Urca processes. We consider two regimes of interest: (a) the neutrino-transparent regime with T≤Ttr (Ttr≃5÷10 MeV is the neutrino-trapping temperature); and (b) the neutrino-trapped regime with T≥Ttr. Nuclear matter is modeled in relativistic density functional approach with density-dependent parametrization DDME2. The maximum of the bulk viscosity is achieved at temperatures T≃5÷6 MeV in the neutrino-transparent regime, then it drops rapidly at higher temperatures where neutrino-trapping occurs. As an astrophysical application, we estimate the damping timescales of density oscillations by the bulk viscosity in neutron star mergers and find that, e.g., at the oscillation frequency f=10 kHz, the damping will be very efficient at temperatures 4≤T≤7 MeV where the bulk viscosity might affect the evolution of the post-merger object.