Speaker
Description
Medium effects, which can be introduced in the Skyrme formalism as density-dependent or three-body forces, are an essential part of describing hyperonic interactions. In neutron stars, these effects are especially important due to the extremely high densities.
We study the influence of the different aspects of these medium effects on neutron stars characteristics. In particular, the role of $\gamma$ in the dependence of $\Lambda N$-interaction on nucleon density $\rho_N^\gamma$ in description of neutron stars is studied. Known Skyrme parametrizations of $\Lambda N$-interaction with $\gamma<1$ provide softer equations of state and smaller masses of neutron stars than those with $\gamma =1$. However, we show that it is not necessarily so and parametrizations with lower value of $\gamma$ can provide stiffer equations of state. We also compare the density-dependent $\Lambda N$ forces to the three-body $\Lambda NN$ forces. The latter in neutron stars lead to a softer equation of state and can, in some cases, considerably affect the chemical composition of the star.
Finally, we include a density dependence to the $\Lambda \Lambda$ potential and compare the obtained potential with known potentials of $\Lambda \Lambda$-interaction.
This work was supported by the Russian Science Foundation under Grant No 24-22-00077.
