Dust sphere metric
Constants:
Constants(k);
 | (2.1) |
Functions:
Functions(lambda=lambda(tau,R),r=r(tau,R),epsilon=epsilon(tau,R));
 | (2.2) |
Vector fields:
Vectors(E[i],X,Y,Z);
![{X, Y, Z, E[i]}](Maple/atlas/Templates/images/dust_10.gif) | (2.3) |
Differential p-forms:
Forms(e[j]=1);
![{e[j]}](Maple/atlas/Templates/images/dust_11.gif) | (2.4) |
Coframe 1-forms:
Coframe(e[1]=d(tau),e[2]=d(R),e[3]=d(theta),e[4]=d(phi));
![[e[1] = d(tau), e[2] = d(R), e[3] = d(theta), e[4] = d(phi)]](Maple/atlas/Templates/images/dust_12.gif) | (2.5) |
Frame vector fields:
Frame(E[i]);
![[E[1] = Diff(``, tau), E[2] = Diff(``, R), E[3] = Diff(``, theta), E[4] = Diff(``, phi)]](Maple/atlas/Templates/images/dust_13.gif) | (2.6) |
Metric tensor field:
Metric( g=d(tau)&.d(tau)-exp(lambda)*d(R)&.d(R)-r^2*(d(theta)&.d(theta)+sin(theta)^2*d(phi)&.d(phi)) );
![g = `+`(`&.`(e[1], e[1]), `-`(`*`(exp(lambda), `*`(`&.`(e[2], e[2])))), `-`(`*`(`^`(r, 2), `*`(`+`(`&.`(e[3], e[3]), `*`(`^`(sin(theta), 2), `*`(`&.`(e[4], e[4]))))))))](Maple/atlas/Templates/images/dust_14.gif)
![g = `+`(`&.`(e[1], e[1]), `-`(`*`(exp(lambda), `*`(`&.`(e[2], e[2])))), `-`(`*`(`^`(r, 2), `*`(`+`(`&.`(e[3], e[3]), `*`(`^`(sin(theta), 2), `*`(`&.`(e[4], e[4]))))))))](Maple/atlas/Templates/images/dust_15.gif) | (2.7) |
Connection 1-forms:
Connection(omega);
![omega[i, j]](Maple/atlas/Templates/images/dust_16.gif) | (2.8) |
Curvature 2-forms:
Curvature(Omega);
![Omega[i, j]](Maple/atlas/Templates/images/dust_17.gif) | (2.9) |
Curvature tensor field:
Riemann(Riem);
Ricci tensor field calculation:
| > | Einstein:=collect(ric-1/2*scal*ToBasis(g),`&.`,factor); |
Energy-momentum tensor for dust sphere:
T:=epsilon*e[1]&.e[1];
![`*`(epsilon, `*`(`&.`(e[1], e[1])))](Maple/atlas/Templates/images/dust_57.gif) | (2.14) |
| > | eqs:=Einstein=8*Pi*k*T: 'Einstein'=8*Pi*k*T; |
![Einstein = `+`(`*`(8, `*`(Pi, `*`(k, `*`(epsilon, `*`(`&.`(e[1], e[1])))))))](Maple/atlas/Templates/images/dust_58.gif) | (2.15) |
"eqs" tensor components:
| > | eq[1,1]:=iota[E[1],E[1]](eqs); |

 | (2.16) |
| > | eq[2,2]:=iota[E[2],E[2]](eqs); |
 | (2.17) |
| > | eq[3,3]:=iota[E[3],E[3]](eqs); |

 | (2.18) |
| > | eq[1,2]:=iota[E[2],E[1]](eqs); |
 | (2.19) |
Verify that
are Killing vector field but
is not:
| > | 'L[E[4]](g)'=L[E[4]](g); |
![L[E[4]](g) = 0](Maple/atlas/Templates/images/dust_67.gif) | (2.20) |
| > | 'L[E[1]](g)'=L[E[1]](g); |
![L[E[1]](g) = `+`(`-`(`*`(exp(lambda), `*`(Diff(lambda, tau), `*`(`&.`(e[2], e[2]))))), `-`(`*`(2, `*`(r, `*`(Diff(r, tau), `*`(`+`(`&.`(e[3], e[3]), `*`(`^`(sin(theta), 2), `*`(`&.`(e[4], e[4]))))))))...](Maple/atlas/Templates/images/dust_68.gif)
![L[E[1]](g) = `+`(`-`(`*`(exp(lambda), `*`(Diff(lambda, tau), `*`(`&.`(e[2], e[2]))))), `-`(`*`(2, `*`(r, `*`(Diff(r, tau), `*`(`+`(`&.`(e[3], e[3]), `*`(`^`(sin(theta), 2), `*`(`&.`(e[4], e[4]))))))))...](Maple/atlas/Templates/images/dust_69.gif) | (2.21) |
Using covariant derivative:
| > | 'cov(E[i],e[1]&^e[2])'=cov(E[i],e[1]&^e[2]); |