Speaker
Description
We introduce a model-independent mechanism to merge two (or more) equations of state (EoS) by treating them as a two-fluid statistical mixture in the Grand Canonical Ensemble. The merged grand-potential density $\omega(T,\mu_B)$ is built directly from the input EoS, and the fluid fraction is fixed by minimizing $\omega$ at fixed $(T,\mu_B)$. Thermodynamic consistency is enforced across all observables. This construction satisfies the Maxwell relations and enforces convexity of the pressure $ P(T,\mu_B)$. All quantities are derived from a single merged grand potential $\Omega$ as a function of $T$ and $\mu_B$. This yields smooth, differentiable fields over the $T$–$\mu_B$ plane. The method can be modified to accommodate a first-order phase transition and critical point on the phase diagram. Implementing this mechanism, we merge a van der Waals hadron resonance gas EoS with a holographic Einstein Maxwell Dilaton EoS. The result is a single EoS, spanning hadronic to deconfined matter over a broad range in $(T,\mu_B)$. It has immediate applications to heavy-ion hydrodynamics simulations. This construction may be generalized to more than two input EoSs.
