We explore the effects of strangeness and $\mathrm{\Delta }$ resonance in baryonic matter and compact stars within the relativistic-mean-field models. The parameter set PKDD is adopted for $N\text{−}N$ interaction, parameters fixed based on finite hypernuclei and neutron stars are taken for the hyperon-meson couplings, and the universal baryon-meson coupling scheme is adopted for the $\mathrm{\Delta }$-meson couplings. In light of the recent observations of GW170817 with the dimensionless combined tidal deformability $197\le \overline{\mathrm{\Lambda }}\le 720$, we find it is essential to include the $\mathrm{\Delta }$ resonances in compact stars, and small $\mathrm{\Delta }\text{−}\rho$ coupling $g_{\rho \mathrm{\Delta }}$ is favored if the mass ${2.27}_{-0.15}^{+0.17}{M}_{\odot }$ of PSR $\mathrm{J}2215+5135$ is confirmed.

• Received 7 August 2018
• Revised 6 October 2018

DOI:https://doi.org/10.1103/PhysRevD.99.023004