Bayesian Analysis of Neutron Star Mass and Radius Observations
Public Member Functions
bamr::fixed_pressure Class Reference

Fix pressure on a grid of energy densities. More...

Detailed Description

Referred to as Model C in Steiner13tn.

Instead of polytropes, linearly interpolate pressures on a fixed grid of energy densities. The schematic EOS is used up to an energy density of $ 1~\mathrm{fm^{-4}} $. The last four parameters are pressures named pres1 through pres4. Then the line segments are defined by the points

\begin{eqnarray*} P(2~\mathrm{fm}^{-4}) - P(1~\mathrm{fm}^{-4}) = \mathrm{pres1}; \quad P(3~\mathrm{fm}^{-4}) - P(2~\mathrm{fm}^{-4}) = \mathrm{pres2}; \quad P(5~\mathrm{fm}^{-4}) - P(3~\mathrm{fm}^{-4}) = \mathrm{pres3}; \quad P(7~\mathrm{fm}^{-4}) - P(5~\mathrm{fm}^{-4}) = \mathrm{pres4} \end{eqnarray*}

The final line segment is extrapolated up to $ \varepsilon = 10~\mathrm{fm^{-4}} $

For a linear EOS, $ P = P_1 + c_s^2 (\varepsilon-\varepsilon_1) $ , beginning at a pressure of $ P_1 $ , an energy density of $ \varepsilon_1 $ and a baryon density of $ n_{B,1} $, the baryon density is

\[ n_B = n_{B,1} \left\{ \frac{\left[\varepsilon+ P_1+c_s^2(\varepsilon-\varepsilon_1)\right]} {\varepsilon_1+P_1} \right\}^{1/(1+c_s^2)} \]

Definition at line 305 of file models.h.

#include <models.h>

Inheritance diagram for bamr::fixed_pressure:
bamr::two_polytropes bamr::model

Public Member Functions

virtual void low_limits (entry &e)
 Set the lower boundaries for all the parameters, masses, and radii.
 
virtual void high_limits (entry &e)
 Set the upper boundaries for all the parameters, masses, and radii.
 
virtual std::string param_name (size_t i)
 Return the name of parameter with index i.
 
virtual std::string param_unit (size_t i)
 Return the unit of parameter with index i.
 
virtual void compute_eos (entry &e, int &success, std::ofstream &scr_out)
 Compute the EOS corresponding to parameters in e and put output in tab_eos.
 
virtual void first_point (entry &e)
 Function to compute the initial guess.
 
- Public Member Functions inherited from bamr::two_polytropes
virtual void setup_params (o2scl::cli &cl)
 Setup new model parameters.
 
virtual void remove_params (o2scl::cli &cl)
 Remove model-specific parameters.
 
virtual void baryon_density_point (double &n1, double &e1)
 A point to calibrate the baryon density with. More...
 
 two_polytropes ()
 Create a model object.
 
- Public Member Functions inherited from bamr::model
virtual void compute_mr (entry &e, std::ofstream &scr_out, o2scl::o2_shared_ptr< o2scl::table_units<> >::type tab_mvsr, int &success)
 Compute the M-R curve directly.
 

Additional Inherited Members

- Data Fields inherited from bamr::model
nstar_cold2 cns
 TOV solver and storage for the EOS table.
 
- Protected Attributes inherited from bamr::two_polytropes
o2scl::cli::parameter_double p_kin_sym
 Parameter for kinetic part of symmetry energy.
 
o2scl::eos_had_schematic se
 Low-density EOS.
 
o2scl::fermion neut
 Neutron for se.
 
o2scl::fermion prot
 Proton for se.
 
double nb_n1
 The fiducial baryon density.
 
double nb_e1
 The fiducial energy density.
 
The documentation for this class was generated from the following file:

Documentation generated with Doxygen. Bamr documentation is under the GNU Free Documentation License.