Possible maximum mass of dark matter existing in compact stars based on the self-interacting fermionic model

Abstract

By assuming that only gravitation acts between dark matter (DM) and normal matter (NM), we studied DM admixed neutron stars (DANSs) using the two-fluid TOV equations. The NM and DM of compact stars are simulated by the relativistic mean field (RMF) theory and nonself-annihilating self-interacting fermionic model, respectively. The effects of the particle mass of fermionic DM m f and the interaction strength parameter y on the properties of DANSs are investigated in detail. m f and y are considered as the free parameters due to the lack of information about the particle nature of DM so far. For a DANS, we suggest a simple universal relationship M max D = (0.267y + 0.627 − 3.21 M N M )( 1GeV m f ) 2 M for y > 100, where M max D is the maximum mass of DM existing in DANSs and M N is the mass of the neutron star without DM. For free fermion DM model (y=0), the relationship becomes M max D = (0.627 − 0.027 M 2 N M 2 )( 1GeV m f ) 2 M . The radius of DM R D shows a linear relationship with M max D in DANSs, namely R D = (7.02 M max D M + 1.36) km. These conclusions are independent of the different NM EOSs from RMF theory. Such a kind of universal relationship connecting the nature of DM particle and mass of stars might shed light on the constraining the nature of the DM by indirect method.

Dark Matter Admixed Neutron Star Properties in the Light of X-Ray Pulse Profile Observations

“…Multimessenger observations have been explored to constrain the structure of DM-admixed NSs (DANSs), which in turn puts limits on the DM parameter space. In this context, there are many studies of how DM may impact various observable properties of NSs, such as the mass-radius relation (Narain et al 2006;Sandin & Ciarcelluti 2009;Ciarcelluti & Sandin 2011;Leung et al 2011;Leung et al 2012;Goldman et al 2013;Xiang et al 2014;Kouvaris & Nielsen 2015;Li et al 2015;Mukhopadhyay et al 2017;Panotopoulos & Lopes 2017;Rezaei 2017;Motta et al 2018;Wang et al 2019), the surface temperature (Bertone & Fairbairn 2008;Kouvaris 2008;de Lavallaz & Fairbairn 2010;Gonzalez & Reisenegger 2010;Kouvaris & Tinyakov 2010;Fan et al 2011), the kinematics and rotation properties (Pérez-García & Silk 2012), the tidal deformability (Ellis et al 2018;Das et al 2019;Nelson et al 2019;Das et al 2020;Fasano et al 2020;Quddus et al 2020;Das et al 2021;Husain & Thomas 2021;Lee et al 2021;Sagun et al 2021;Sen & Guha 2021;Dengler et al 2022;Di Giovanni et al 2022;Rafiei Karkevandi et al 2022), or the gravitational-wave waveform during the postmerger stage (Kopp et al 2018;Bezares et al 2019;…”

Strange stars with a mirror-dark-matter core confronting with the observations of compact stars

“…Compact stars might contain a dark-matter core made of selfinteracting dark matter [16,17,18]. Neutron stars (NSs) and SSs with a dark-matter core have been studied extensively [e.g., 19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35]. Especially, Neutron stars with a MDM core have been studied [36,37].…”