5th International Symposium on Nuclear Symmetry Energy NuSYM15, June 29 - July 2, 2015 Kraków, POLAND

Chikako Ishizuka
RLNR, Tokyo Institute of Technology, JAPAN

EOSDB: The database for nuclear equations of state

Nuclear equation of state (EOS) plays an important role in understanding the formation of compact objects such as neutron stars and black holes. The true nature of the EOS has been a matter of debate at any density range not only in nuclear physics but also in astronomy and astrophysics. Recently, based on astrophysical perspectives, two EOS databases have been developed. One is ours, called EOSDB, and contains the basic properties of the nuclear EOS of symmetric nuclear matter and of pure neutron matter. It also includes the detailed information about the theoretical models, for example the adopted methods and assumptions in individual models. The novelty of the database is to consider new experimental probes such as symmetry energy, its slope relative to baryon density, and incompressibility, which enables the users to check their model dependence. The other database is the CompOSE database from the CompStar project. This provides EOS tables with nuclear statistical equilibrium (NSE) approximation for the inhomogeneous phase below the nuclear saturation density. It has been developed for the calculations of astrophysical phenomena at finite temperatures such as supernova explosions and neutron star mergers. In order to study EOSs from all aspects, the two teams, the EOSDB and the CompOSE, have started to collaborate. In this presentation, we will demonstrate the performance of the EOSDB by examining the model dependence in different nuclear EOSs. It is revealed that some theoretical EOSs, which are commonly used in astrophysics, do not satisfactorily agree with the experimental constraints. We will also introduce our plan to compile and provide the common EOSs between these two systems.

C. Ishizuka et al., Publ Astron Soc Jpn (February 2015) 67 (1): 13
S. Typel et al., arXiv:1307.5715