Newman-Penrose Operators

  The four Newman-Penrose operators require the existence of the connection object and operate on algebraic expressions. They are defined as follows: <<2195>

The REDTEN functions npD(), npDEL(), npdel(), and npdelc() implement each of the operators, respectively. For example,

 
#: npD(th*sin(r));

  sqrt(2) cos(r) th
 -------------------
          2

#: npDEL(th*sin(r));

   - sqrt(2) cos(r) delta th
 ----------------------------
           ____
         4 rhob rhob

#: npdel(th*sin(r));

  sin(r)
 --------
  2 rhob

#: npdelc(th*sin(r));

  sin(r)
 --------
    ____
  2 rhob