star_rot_global.C

/*
 * Methods for computing global quantities within the class Star_rot
 *
 * (see file star_rot.h for documentation)
 */

/*
 *   Copyright (c) 2010 Eric Gourgoulhon
 *
 *   This file is part of LORENE.
 *
 *   LORENE is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   LORENE is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with LORENE; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


 

/*
 * $Id: star_rot_global.C,v 1.13 2026/01/20 08:35:28 j_novak Exp $
 * $Log: star_rot_global.C,v $
 * Revision 1.13  2026/01/20 08:35:28  j_novak
 * New method radius_Morsink() to compute the physical radius along the definition of Morsink et al. (2007) in the oblate Schwarschild approximation.
 *
 * Revision 1.12  2026/01/19 13:04:23  j_novak
 * Corrected the location of the surface in surf_gravity()
 *
 * Revision 1.11  2023/07/04 09:01:09  j_novak
 * Changed the name r_pol_circ -> r_circ_merid to explicitly show the radius is a circumferential one, along a meridian.
 *
 * Revision 1.10  2023/07/03 14:32:31  j_novak
 * Added method "r_pol_circ()", to compute polar circumferential radius, with a circumference along a meridian.
 *
 * Revision 1.9  2021/10/06 09:41:28  j_novak
 * Corrected quadrupole computation from Friedman & Stergioulas book
 *
 * Revision 1.8  2017/04/13 09:59:34  m_bejger
 * Bug fix (contraction using physical gamma metric in surf_grav - vector a)
 *
 * Revision 1.7  2017/04/11 10:46:55  m_bejger
 * Star_rot::surf_grav() - surface gravity values along the theta direction
 *
 * Revision 1.6  2016/12/05 16:18:15  j_novak
 * Suppression of some global variables (file names, loch, ...) to prevent redefinitions
 *
 * Revision 1.5  2015/05/19 09:30:56  j_novak
 * New methods for computing the area of the star and its mean radius.
 *
 * Revision 1.4  2014/10/13 08:53:39  j_novak
 * Lorene classes and functions now belong to the namespace Lorene.
 *
 * Revision 1.3  2014/10/06 15:13:17  j_novak
 * Modified #include directives to use c++ syntax.
 *
 * Revision 1.2  2010/01/25 22:33:35  e_gourgoulhon
 * Debugging...
 *
 * Revision 1.1  2010/01/25 18:15:52  e_gourgoulhon
 * First version.
 * 
 *
 *
 * $Header: /cvsroot/Lorene/C++/Source/Star/star_rot_global.C,v 1.13 2026/01/20 08:35:28 j_novak Exp $
 *
 */

// Headers C
#include <cstdlib>
#include <cmath>

// Headers Lorene
#include "star_rot.h"
#include "unites.h"

            //--------------------------//
            //  Stellar surface     //
            //--------------------------//

namespace Lorene {
  const Itbl& Star_rot::l_surf() const {
    
    if (p_l_surf == 0x0) {    // a new computation is required
      
      assert(p_xi_surf == 0x0) ;  // consistency check
      
      int np = mp.get_mg()->get_np(0) ;   
      int nt = mp.get_mg()->get_nt(0) ;   
      
      p_l_surf = new Itbl(np, nt) ;
      p_xi_surf = new Tbl(np, nt) ;
      
      double ent0 = 0 ; // definition of the surface
      double precis = 1.e-15 ; 
      int nitermax = 100 ; 
      int niter ; 
      
      (ent.get_spectral_va()).equipot(ent0, nzet, precis, nitermax, niter, *p_l_surf, 
                      *p_xi_surf) ; 
      
    }
    
    return *p_l_surf ; 
    
  }
  
                    //------------------------------//
                    //         Baryon mass      //
                    //------------------------------//
  
  double Star_rot::mass_b() const {
    
    if (p_mass_b == 0x0) {    // a new computation is required
      
      if (relativistic) {
    
    Scalar dens = a_car * bbb * gam_euler * nbar ;
    
    p_mass_b = new double( dens.integrale() ) ; 
      }
      else{  // Newtonian case 
    assert(nbar.get_etat() == ETATQCQ) ; 
    
    p_mass_b = new double( nbar.integrale() ) ;
    
      }
      
    }
    return *p_mass_b ; 
  } 


            //----------------------------//
            //  Gravitational mass    //
            //----------------------------//

  double Star_rot::mass_g() const {
    
    if (p_mass_g == 0x0) {    // a new computation is required
      
      if (relativistic) {
    
    Scalar source = nn * (ener_euler + s_euler) 
      + 2 * bbb * (ener_euler + press)
      * tnphi * uuu ; 
    source = a_car * bbb * source ;
    source.std_spectral_base() ; 
    
    p_mass_g = new double( source.integrale() ) ;   
      }
      else{  // Newtonian case 
    p_mass_g = new double( mass_b() ) ;   // in the Newtonian case
                                          //  M_g = M_b
      }
    }
    return *p_mass_g ; 
} 
        
            //----------------------------//
            //  Angular momentum      //
            //----------------------------//

  double Star_rot::angu_mom() const {
    
    if (p_angu_mom == 0x0) {    // a new computation is required
      
      Scalar dens = uuu ; 
      
      dens.mult_r() ;           //  Multiplication by
      dens.set_spectral_va() = (dens.get_spectral_va()).mult_st() ; //    r sin(theta)
      
      if (relativistic) {
    dens = a_car * b_car * (ener_euler + press) * dens ; 
      }
      else {    // Newtonian case 
    dens = nbar * dens ; 
      }
      
      p_angu_mom = new double( dens.integrale() ) ; 
    }
    return *p_angu_mom ; 
  }


            //----------------------------//
            //       T/W          //
            //----------------------------//

  double Star_rot::tsw() const {
    
    if (p_tsw == 0x0) {    // a new computation is required
      
      double tcin = 0.5 * omega * angu_mom() ;
      
      if (relativistic) {
    
    Scalar dens = a_car * bbb * gam_euler * ener ;
    double mass_p = dens.integrale() ; 
    
    p_tsw = new double( tcin / ( mass_p + tcin - mass_g() ) ) ;     
    
      }
      else {        // Newtonian case 
    Scalar dens = 0.5 * nbar * logn ;
    double wgrav = dens.integrale() ; 
    p_tsw = new double( tcin / fabs(wgrav) ) ;  
      } 
    }
    return *p_tsw ; 
}


            //----------------------------//
            //       GRV2         //
            //----------------------------//

double Star_rot::grv2() const {

      using namespace Unites ;  
      if (p_grv2 == 0x0) {    // a new computation is required
    
    Scalar sou_m(mp) ; 
    if (relativistic) {
      sou_m =  2 * qpig * a_car * (press + (ener_euler+press)
                       * uuu*uuu ) ;
        }
    else {
      sou_m = 2 * qpig * (press + nbar * uuu*uuu ) ;
    }
    
    Vector dlogn = logn.derive_cov( mp.flat_met_spher() ) ; 
        Scalar sou_q =  1.5 * ak_car
      - dlogn(1)*dlogn(1) - dlogn(2)*dlogn(2) - dlogn(3)*dlogn(3) ; 
    
    p_grv2 = new double( double(1) - lambda_grv2(sou_m, sou_q) ) ; 
    
      }
    
      return *p_grv2 ; 
      
}


            //----------------------------//
            //       GRV3         //
            //----------------------------//

double Star_rot::grv3(ostream* ost) const {

  using namespace Unites ;  
  
  if (p_grv3 == 0x0) {    // a new computation is required

    Scalar source(mp) ; 
    
    // Gravitational term [cf. Eq. (43) of Gourgoulhon & Bonazzola
    // ------------------       Class. Quantum Grav. 11, 443 (1994)]
    
    Vector dlogn = logn.derive_cov( mp.flat_met_spher() ) ;

    if (relativistic) {
      Scalar alpha = dzeta - logn ; 
      Scalar bet = log( bbb ) ; 
      bet.std_spectral_base() ; 
      
      Vector dalpha = alpha.derive_cov( mp.flat_met_spher() ) ;
      Vector dbet = bet.derive_cov( mp.flat_met_spher() ) ;

      source = 0.75 * ak_car 
    - dlogn(1)*dlogn(1) - dlogn(2)*dlogn(2) - dlogn(3)*dlogn(3) 
    + 0.5 * ( dalpha(1)*dbet(1) + dalpha(2)*dbet(2) + dalpha(3)*dbet(3) ) ; 
      
      Scalar aa = alpha - 0.5 * bet ; 
      Scalar daadt = aa.srdsdt() ;  // 1/r d/dth
        
      // What follows is valid only for a mapping of class Map_radial : 
      const Map_radial* mpr = dynamic_cast<const Map_radial*>(&mp) ; 
      if (mpr == 0x0) {
    cout << "Star_rot::grv3: the mapping does not belong"
         << " to the class Map_radial !" << endl ; 
    abort() ; 
      }
      
      // Computation of 1/tan(theta) * 1/r daa/dtheta
      if (daadt.get_etat() == ETATQCQ) {
    Valeur& vdaadt = daadt.set_spectral_va() ; 
    vdaadt = vdaadt.ssint() ;   // division by sin(theta)
    vdaadt = vdaadt.mult_ct() ; // multiplication by cos(theta)
      }
      
      Scalar temp = aa.dsdr() + daadt ; 
      temp = ( bbb - a_car/bbb ) * temp ; 
      temp.std_spectral_base() ; 
      
      // Division by r 
      Valeur& vtemp = temp.set_spectral_va() ; 
      vtemp = vtemp.sx() ;    // division by xi in the nucleus
      // Id in the shells
      // division by xi-1 in the ZEC
      vtemp = (mpr->xsr) * vtemp ; // multiplication by xi/r in the nucleus
      //          by 1/r in the shells
      //          by r(xi-1) in the ZEC
      
      // In the ZEC, a multiplication by r has been performed instead
      //   of the division:             
      temp.set_dzpuis( temp.get_dzpuis() + 2 ) ;  
      
      source = bbb * source + 0.5 * temp ; 
      
    }
    else{
      source = - 0.5 * ( dlogn(1)*dlogn(1) + dlogn(2)*dlogn(2) + dlogn(3)*dlogn(3) ) ; 
    }
    
    source.std_spectral_base() ; 
    
    double int_grav = source.integrale() ; 
    
    // Matter term
    // -----------
    
    if (relativistic) {    
      source  = qpig * a_car * bbb * s_euler ;
    }
    else{
      source = qpig * ( 3 * press + nbar * uuu * uuu ) ; 
    }
    
    source.std_spectral_base() ; 

    double int_mat = source.integrale() ; 
    
    // Virial error
    // ------------
    if (ost != 0x0) {
      *ost << "Star_rot::grv3 : gravitational term : " << int_grav 
       << endl ;
      *ost << "Star_rot::grv3 : matter term :        " << int_mat 
       << endl ;
    }
    
    p_grv3 = new double( (int_grav + int_mat) / int_mat ) ;      
    
  }
  
  return *p_grv3 ; 
  
}


            //----------------------------//
            //       R_circ       //
            //----------------------------//

double Star_rot::r_circ() const {

    if (p_r_circ == 0x0) {    // a new computation is required
    
    // Index of the point at phi=0, theta=pi/2 at the surface of the star:
    const Mg3d* mg = mp.get_mg() ; 
    assert(mg->get_type_t() == SYM) ; 
    int l_b = nzet - 1 ; 
    int i_b = mg->get_nr(l_b) - 1 ; 
    int j_b = mg->get_nt(l_b) - 1 ; 
    int k_b = 0 ; 
    
    p_r_circ = new double( bbb.val_grid_point(l_b, k_b, j_b, i_b) * ray_eq() ) ; 

    }
    
    return *p_r_circ ; 

}

double Star_rot::r_circ_merid() const {

    if (p_r_circ_merid == 0x0) {    // a new computation is required
      const Mg3d& mg = *(mp.get_mg()) ; 
      int np = mg.get_np(0) ;
      int nt = mg.get_nt(0) ;
      assert(np == 1) ; //Only valid for axisymmetric configurations
      
      const Map_radial* mp_rad = dynamic_cast<const Map_radial*>(&mp) ;
      assert(mp_rad != 0x0) ;

      Valeur va_r(mg.get_angu()) ;
      va_r.annule_hard() ;
      Itbl lsurf = l_surf() ;
      Tbl xisurf = xi_surf() ;
      for (int k=0; k<np; k++) {
    for (int j=0; j<nt; j++) {
      int l_star = lsurf(k, j) ;
      double xi_star = xisurf(k, j) ;
      va_r.set(0, k, j, 0) = mp_rad->val_r_jk(l_star, xi_star, j, k) ;
    }
      }
      va_r.std_base_scal() ;
      
      Valeur integ(mg.get_angu()) ;
      Valeur dr = va_r.dsdt() ;
      integ = sqrt(va_r*va_r + dr*dr) ;
      Valeur a2 = get_a_car().get_spectral_va() ; a2.std_base_scal() ;
      int k = 0 ;
      for (int j=0; j<nt; j++) {
    integ.set(0, k, j, 0)
      *= sqrt(a2.val_point_jk(lsurf(k, j), xisurf(k, j), j, k)) ;
      }
      integ.std_base_scal() ;
      integ.coef() ;
      double surftot = (*integ.c_cf)(0, k, 0, 0) ; // Only j=0 has a nonvanishing 
                                                   // integral
      p_r_circ_merid = new double(surftot ) ; 

    }
    
    return *p_r_circ_merid ; 

}

            //----------------------------//
            //    Surface area        //
            //----------------------------//

  double Star_rot::area() const {

    if (p_area == 0x0) {    // a new computation is required
      const Mg3d& mg = *(mp.get_mg()) ; 
      int np = mg.get_np(0) ;
      int nt = mg.get_nt(0) ;
      assert(np == 1) ; //Only valid for axisymmetric configurations
      
      const Map_radial* mp_rad = dynamic_cast<const Map_radial*>(&mp) ;
      assert(mp_rad != 0x0) ;

      Valeur va_r(mg.get_angu()) ;
      va_r.annule_hard() ;
      Itbl lsurf = l_surf() ;
      Tbl xisurf = xi_surf() ;
      for (int k=0; k<np; k++) {
    for (int j=0; j<nt; j++) {
      int l_star = lsurf(k, j) ;
      double xi_star = xisurf(k, j) ;
      va_r.set(0, k, j, 0) = mp_rad->val_r_jk(l_star, xi_star, j, k) ;
    }
      }
      va_r.std_base_scal() ;
      
      Valeur integ(mg.get_angu()) ;
      Valeur dr = va_r.dsdt() ;
      integ = sqrt(va_r*va_r + dr*dr) ;
      Valeur a2 = get_a_car().get_spectral_va() ; a2.std_base_scal() ;
      Valeur b = get_bbb().get_spectral_va() ; b.std_base_scal() ;
      for (int k=0; k<np; k++) {
    for (int j=0; j<nt; j++) {
      integ.set(0, k, j, 0) *= sqrt(a2.val_point_jk(lsurf(k, j), xisurf(k, j), j, k))
        * b.val_point_jk(lsurf(k, j), xisurf(k, j), j, k) * va_r(0, k, j, 0) ;
    }
      }
      integ.std_base_scal() ;
      Valeur integ2 = integ.mult_st() ;
      double surftot = 0. ;
      for (int j=0; j<nt; j++) {
    surftot += (*integ2.c_cf)(0, 0, j, 0) / double(2*j+1) ;
      }
      
      p_area = new double( 4*M_PI*surftot) ;

    }
    
    return *p_area ; 

}

  double Star_rot::mean_radius() const {

    return sqrt(area()/(4*M_PI)) ;

  }

            //----------------------------//
            //     Flattening         //
            //----------------------------//

double Star_rot::aplat() const {

    if (p_aplat == 0x0) {    // a new computation is required
    
    p_aplat = new double( ray_pole() / ray_eq() ) ;      

    }
    
    return *p_aplat ; 

}


            //----------------------------//
            //       Z_eq_f       //
            //----------------------------//

double Star_rot::z_eqf() const {

    if (p_z_eqf == 0x0) {    // a new computation is required
    
    // Index of the point at phi=0, theta=pi/2 at the surface of the star:
    const Mg3d* mg = mp.get_mg() ; 
    assert(mg->get_type_t() == SYM) ; 
    int l_b = nzet - 1 ; 
    int i_b = mg->get_nr(l_b) - 1 ; 
    int j_b = mg->get_nt(l_b) - 1 ; 
    int k_b = 0 ; 
    
    double u_eq = uuu.val_grid_point(l_b, k_b, j_b, i_b) ; 
    double n_eq = nn.val_grid_point(l_b, k_b, j_b, i_b) ; 
    double nphi_eq = nphi.val_grid_point(l_b, k_b, j_b, i_b) ; 
    
    p_z_eqf = new double( sqrt((1.-u_eq)/(1.+u_eq)) 
                / (n_eq + nphi_eq * r_circ() )
                  - 1. ) ;
    }
    
    return *p_z_eqf ; 

}
            //----------------------------//
            //       Z_eq_b       //
            //----------------------------//

double Star_rot::z_eqb() const {

    if (p_z_eqb == 0x0) {    // a new computation is required
    
    // Index of the point at phi=0, theta=pi/2 at the surface of the star:
    const Mg3d* mg = mp.get_mg() ; 
    assert(mg->get_type_t() == SYM) ; 
    int l_b = nzet - 1 ; 
    int i_b = mg->get_nr(l_b) - 1 ; 
    int j_b = mg->get_nt(l_b) - 1 ; 
    int k_b = 0 ; 
    
    double u_eq = uuu.val_grid_point(l_b, k_b, j_b, i_b) ; 
    double n_eq = nn.val_grid_point(l_b, k_b, j_b, i_b) ; 
    double nphi_eq = nphi.val_grid_point(l_b, k_b, j_b, i_b) ; 
    
    p_z_eqb = new double(  sqrt((1.+u_eq)/(1.-u_eq)) 
                / (n_eq - nphi_eq * r_circ() )
                  - 1. )  ;

    }
    
    return *p_z_eqb ; 

}


            //----------------------------//
            //       Z_pole       //
            //----------------------------//

double Star_rot::z_pole() const {

    if (p_z_pole == 0x0) {    // a new computation is required
    
    double n_pole = nn.val_point(ray_pole(), 0., 0.) ; 
    
    p_z_pole = new double(  1. / n_pole - 1. ) ; 

    }
    
    return *p_z_pole ; 

}


            //----------------------------//
            //     Quadrupole moment      //
                        // Uses Eq.(11) of Pappas &   //
                        // Apostolatos, PRL 108 2012  //
            //----------------------------//

double Star_rot::mom_quad() const {

  using namespace Unites ;
    if (p_mom_quad == 0x0) {    // a new computation is required
    
    // Source for of the Poisson equation for nu
    // -----------------------------------------

    Scalar source(mp) ; 
    
    if (relativistic) {
        Scalar bet = log(bbb) ; 
        bet.std_spectral_base() ; 
        
        Vector dlogn = logn.derive_cov( mp.flat_met_spher() ) ;
        Vector dlogn_bet = dlogn + bet.derive_cov( mp.flat_met_spher() ) ;

        source =  qpig * a_car *( ener_euler + s_euler ) + ak_car 
          - dlogn(1)*dlogn_bet(1) - dlogn(2)*dlogn_bet(2) - dlogn(3)*dlogn_bet(3)   ; 
    }
    else {
        source = qpig * nbar ; 
    }
    
    source.std_spectral_base() ;

    // Multiplication by -r^2 P_2(cos(theta))
    //  [cf Eq.(7) of Salgado et al. Astron. Astrophys. 291, 155 (1994) ]
    // ------------------------------------------------------------------
    
    // Multiplication by r^2 : 
    // ----------------------
    source.mult_r() ; 
    source.mult_r() ; 
    if (source.check_dzpuis(2)) {
        source.inc_dzpuis(2) ; 
    }
        
    // Muliplication by cos^2(theta) :
    // -----------------------------
    Scalar temp = source ; 
    
    // What follows is valid only for a mapping of class Map_radial : 
    assert( dynamic_cast<const Map_radial*>(&mp) != 0x0 ) ; 
        
    if (temp.get_etat() == ETATQCQ) {
        Valeur& vtemp = temp.set_spectral_va() ; 
        vtemp = vtemp.mult_ct() ;   // multiplication by cos(theta)
        vtemp = vtemp.mult_ct() ;   // multiplication by cos(theta)
    }
    
    // Muliplication by -P_2(cos(theta)) :
    // ----------------------------------
    source = 0.5 * source - 1.5 * temp ; 
    
    // First part
    // ------------

    p_mom_quad = new double( -source.integrale() / qpig ) ;

    // Correction terms from (3.37) of Friedman & Stergioulas' book 
    if (relativistic) { 

      Scalar correct(mp) ;
      correct = a_car * bbb * nn * press ;
      correct.mult_rsint() ;
      correct.std_spectral_base() ; 

      double Bo = -32. * correct.integrale() / qpig ;

      *p_mom_quad -= 4./3. * (1./4. + Bo/(mass_g() * mass_g()))
        * pow(mass_g(), 3) * ggrav * ggrav ;
    }

    }
    
    return *p_mom_quad ; 

}


            //----------------------------//
            //     Surface gravity        //
            //----------------------------//

const Tbl& Star_rot::surf_grav() const {

  using namespace Unites ;
  if (p_surf_grav == 0x0) {    // a new computation is required

    const Mg3d* mg = mp.get_mg() ; 
    assert(mg->get_type_t() == SYM) ; 
    int nt = mg->get_nt(0) ;   // number of theta points  
 
    Scalar loggam = log(gam_euler) ;
    loggam.std_spectral_base() ; 
 
    Vector a = logn.derive_cov( mp.flat_met_spher() ) 
             - loggam.derive_cov( mp.flat_met_spher() ); 

    Scalar g_s = sqrt(contract( a, 0, a.up_down(gamma), 0 )) ;
    g_s.std_spectral_base() ;

    p_surf_grav = new Tbl(nt) ;
    p_surf_grav->set_etat_qcq() ;

    for(int j = 0; j < nt; j++)   {
      int l_b = l_surf()(0, j) ;
      double xi_b = xi_surf()(0, j) ;
      p_surf_grav->set(j) = g_s.get_spectral_va().val_point_jk(l_b, xi_b, j, 0) ;
    }
  } 

  return *p_surf_grav ;   

} 

            //----------------------------//
            //  Circular radius (\theta)  //
            //----------------------------//

const Tbl& Star_rot::radius_Morsink() const {

  using namespace Unites ;
  if (p_radius_Morsink == 0x0) {    // a new computation is required

    const Mg3d* mg = mp.get_mg() ; 
    assert(mg->get_type_t() == SYM) ; 
    int nt = mg->get_nt(0) ;   // number of theta points  
 
    p_radius_Morsink = new Tbl(nt) ;
    p_radius_Morsink->set_etat_qcq() ;
    const Map_radial* mp_rad = dynamic_cast<const Map_radial*>(&mp) ;

    for(int j = 0; j < nt; j++)   {
      int l_b = l_surf()(0, j) ;
      double xi_b = xi_surf()(0, j) ;
      p_radius_Morsink->set(j)
    = bbb.get_spectral_va().val_point_jk(l_b, xi_b, j, 0)
    * mp_rad->val_r_jk(l_b, xi_b, j, 0) ;
    }
  } 

  return *p_radius_Morsink ;   

} 

}