From $\chi$EFT to Multi-Region Modeling: Neutron star structure with a polytropic extension of $\chi$EFT and MUSES Calculation Engine multi-layer modeling

Neutron stars provide a unique environment to probe the properties of dense nuclear matter. In this work, we present a comparative study between two approaches to modeling the neutron star structure: a Chiral Effective Field Theory based approach and the MUSES Calculation Engine framework, which uses three different approaches for the three density regions. We analyze the resulting mass-radius relations, discussing the respective advantages and limitations of the two methods.