Michael_Watson

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These are questions asked by Michael_Watson

Does anyone know an easy way to convert %d_ to D? I tried the convert command, but no effect.  Thanks.

 

Michael

 

restart; with(Physics); with(Tetrads)

0, "%1 is not a command in the %2 package", Tetrads, Physics

(1)

Physics:-Setup(coordinatesystems = {X}, mathematicalnotation = true)

[coordinatesystems = {X}, mathematicalnotation = true]

(2)

Physics:-Define(Ybar[a], Y[a], GammaT[a, b, c], RicciT[b, c] = %d_[c](GammaT[`~a`, b, a])-%d_[a](GammaT[`~a`, b, c])+Physics:-`*`(GammaT[`~m`, b, a], GammaT[`~a`, m, c])-Physics:-`*`(GammaT[`~m`, b, c], GammaT[`~a`, m, a])+Physics:-`*`(GammaT[`~a`, b, m], GammaT[`~m`, c, a]-GammaT[`~m`, a, c]), RiemannT[k, l, m, n] = %d_[k](GammaT[m, n, l])-%d_[l](GammaT[m, n, k])+Physics:-`*`(GammaT[`~a`, m, l], GammaT[a, n, k])-Physics:-`*`(GammaT[`~a`, m, k], GammaT[a, n, l])+Physics:-`*`(GammaT[m, n, a], GammaT[`~a`, k, l]-GammaT[`~a`, l, k]))

RicciT[1, 3]

%d_[3](GammaT[`~1`, 1, 1]+GammaT[`~2`, 1, 2]+GammaT[`~3`, 1, 3]+GammaT[`~4`, 1, 4])+GammaT[`~4`, 1, 2]*GammaT[`~2`, 3, 4]+GammaT[`~1`, 1, 3]*GammaT[`~3`, 3, 1]+GammaT[`~2`, 1, 3]*GammaT[`~3`, 3, 2]+GammaT[`~4`, 1, 3]*GammaT[`~3`, 3, 4]-GammaT[`~2`, 1, 3]*GammaT[`~1`, 2, 1]-GammaT[`~2`, 1, 3]*GammaT[`~2`, 2, 2]-GammaT[`~2`, 1, 3]*GammaT[`~4`, 2, 4]-GammaT[`~3`, 1, 3]*GammaT[`~1`, 3, 1]-GammaT[`~3`, 1, 3]*GammaT[`~2`, 3, 2]-GammaT[`~3`, 1, 3]*GammaT[`~4`, 3, 4]-GammaT[`~4`, 1, 3]*GammaT[`~1`, 4, 1]-GammaT[`~4`, 1, 3]*GammaT[`~2`, 4, 2]-GammaT[`~4`, 1, 3]*GammaT[`~4`, 4, 4]-GammaT[`~1`, 1, 3]*GammaT[`~2`, 1, 2]-GammaT[`~1`, 1, 3]*GammaT[`~4`, 1, 4]+GammaT[`~1`, 1, 4]*GammaT[`~4`, 3, 1]+GammaT[`~2`, 1, 4]*GammaT[`~4`, 3, 2]+GammaT[`~4`, 1, 4]*GammaT[`~4`, 3, 4]+GammaT[`~1`, 1, 1]*GammaT[`~1`, 3, 1]+GammaT[`~2`, 1, 1]*GammaT[`~1`, 3, 2]+GammaT[`~4`, 1, 1]*GammaT[`~1`, 3, 4]+GammaT[`~1`, 1, 2]*GammaT[`~2`, 3, 1]+GammaT[`~2`, 1, 2]*GammaT[`~2`, 3, 2]+GammaT[`~1`, 3, 3]*GammaT[`~3`, 1, 1]+GammaT[`~2`, 3, 3]*GammaT[`~3`, 1, 2]+GammaT[`~3`, 1, 4]*GammaT[`~4`, 3, 3]-GammaT[`~3`, 4, 3]*GammaT[`~4`, 1, 3]-GammaT[`~1`, 1, 1]*GammaT[`~1`, 1, 3]-GammaT[`~1`, 1, 3]*GammaT[`~3`, 1, 3]-GammaT[`~2`, 1, 3]*GammaT[`~3`, 2, 3]-%d_[4](GammaT[`~4`, 1, 3])+%d_[1](GammaT[`~1`, 1, 3])+%d_[3](GammaT[`~3`, 1, 3])+%d_[2](GammaT[`~2`, 1, 3])

(3)

for a to 4 do for b to 4 do RicciT[a, b] end do end do

Error, (in index/PhysicsTensor) expected summation indices of type symbol, received: 1

 

 

Now, if I type the RicciT from (3) it displays the same result. However,......

 

RicciT[1, 3]

%d_[3](GammaT[`~1`, 1, 1]+GammaT[`~2`, 1, 2]+GammaT[`~3`, 1, 3]+GammaT[`~4`, 1, 4])+GammaT[`~4`, 1, 2]*GammaT[`~2`, 3, 4]+GammaT[`~1`, 1, 3]*GammaT[`~3`, 3, 1]+GammaT[`~2`, 1, 3]*GammaT[`~3`, 3, 2]+GammaT[`~4`, 1, 3]*GammaT[`~3`, 3, 4]-GammaT[`~2`, 1, 3]*GammaT[`~1`, 2, 1]-GammaT[`~2`, 1, 3]*GammaT[`~2`, 2, 2]-GammaT[`~2`, 1, 3]*GammaT[`~4`, 2, 4]-GammaT[`~3`, 1, 3]*GammaT[`~1`, 3, 1]-GammaT[`~3`, 1, 3]*GammaT[`~2`, 3, 2]-GammaT[`~3`, 1, 3]*GammaT[`~4`, 3, 4]-GammaT[`~4`, 1, 3]*GammaT[`~1`, 4, 1]-GammaT[`~4`, 1, 3]*GammaT[`~2`, 4, 2]-GammaT[`~4`, 1, 3]*GammaT[`~4`, 4, 4]-GammaT[`~1`, 1, 3]*GammaT[`~2`, 1, 2]-GammaT[`~1`, 1, 3]*GammaT[`~4`, 1, 4]+GammaT[`~1`, 1, 4]*GammaT[`~4`, 3, 1]+GammaT[`~2`, 1, 4]*GammaT[`~4`, 3, 2]+GammaT[`~4`, 1, 4]*GammaT[`~4`, 3, 4]+GammaT[`~1`, 1, 1]*GammaT[`~1`, 3, 1]+GammaT[`~2`, 1, 1]*GammaT[`~1`, 3, 2]+GammaT[`~4`, 1, 1]*GammaT[`~1`, 3, 4]+GammaT[`~1`, 1, 2]*GammaT[`~2`, 3, 1]+GammaT[`~2`, 1, 2]*GammaT[`~2`, 3, 2]+GammaT[`~1`, 3, 3]*GammaT[`~3`, 1, 1]+GammaT[`~2`, 3, 3]*GammaT[`~3`, 1, 2]+GammaT[`~3`, 1, 4]*GammaT[`~4`, 3, 3]-GammaT[`~3`, 4, 3]*GammaT[`~4`, 1, 3]-GammaT[`~1`, 1, 1]*GammaT[`~1`, 1, 3]-GammaT[`~1`, 1, 3]*GammaT[`~3`, 1, 3]-GammaT[`~2`, 1, 3]*GammaT[`~3`, 2, 3]-%d_[4](GammaT[`~4`, 1, 3])+%d_[1](GammaT[`~1`, 1, 3])+%d_[3](GammaT[`~3`, 1, 3])+%d_[2](GammaT[`~2`, 1, 3])

(4)

 

If I type a different RicciT, then ...

 

RicciT[2, 3]

Error, (in index/PhysicsTensor) expected summation indices of type symbol, received: 1

 

 

The for loop is changing the tetrad definition of RicciT.

 

NULL

 

Download Question_about_tetrads_in_for_loop.mw

Some of the Rotation Coefficients are not calculating properly.

Question_about_Ricci_Rotation_Coefficients.mw

 

 


restart; with(Physics); with(Tetrads); with(PDETools)

0, "%1 is not a command in the %2 package", Tetrads, Physics

(1)

coords := zetabar, zeta, v, u

zetabar, zeta, v, u

(2)

X = [coords]

X = [zetabar, zeta, v, u]

(3)

ds2 := Physics:-`*`(Physics:-`*`(2, dzeta), dzetabar)+Physics:-`*`(Physics:-`*`(2, du), dv)+Physics:-`*`(Physics:-`*`(2, H(coords)), Physics:-`^`(du+Physics:-`*`(Ybar(coords), dzeta)+Physics:-`*`(Y(coords), dzetabar)-Physics:-`*`(Physics:-`*`(Y(coords), Ybar(coords)), dv), 2))

2*dzeta*dzetabar+2*du*dv+2*H(zetabar, zeta, v, u)*(du+Ybar(zetabar, zeta, v, u)*dzeta+Y(zetabar, zeta, v, u)*dzetabar-Y(zetabar, zeta, v, u)*Ybar(zetabar, zeta, v, u)*dv)^2

(4)

PDEtools:-declare(ds2)

Ybar(zetabar, zeta, v, u)*`will now be displayed as`*Ybar

(5)

vierbien := Matrix([[1, 0, -Ybar(coords), 0], [0, 1, -Y(coords), 0], [Physics:-`*`(H(coords), Y(coords)), Physics:-`*`(H(coords), Ybar(coords)), 1-Physics:-`*`(Physics:-`*`(H(coords), Y(coords)), Ybar(coords)), H(coords)], [Y(coords), Ybar(coords), -Physics:-`*`(Y(coords), Ybar(coords)), 1]])

vierbien := Matrix(4, 4, {(1, 1) = 1, (1, 2) = 0, (1, 3) = -Ybar(zetabar, Zeta, v, u), (1, 4) = 0, (2, 1) = 0, (2, 2) = 1, (2, 3) = -Y(zetabar, Zeta, v, u), (2, 4) = 0, (3, 1) = H(zetabar, Zeta, v, u)*Y(zetabar, Zeta, v, u), (3, 2) = H(zetabar, Zeta, v, u)*Ybar(zetabar, Zeta, v, u), (3, 3) = 1-H(zetabar, Zeta, v, u)*Y(zetabar, Zeta, v, u)*Ybar(zetabar, Zeta, v, u), (3, 4) = H(zetabar, Zeta, v, u), (4, 1) = Y(zetabar, Zeta, v, u), (4, 2) = Ybar(zetabar, Zeta, v, u), (4, 3) = -Y(zetabar, Zeta, v, u)*Ybar(zetabar, Zeta, v, u), (4, 4) = 1})

(6)

``

Physics:-Setup(coordinatesystem = (X = [zetabar, zeta, v, u]), metric = ds2, tetrad = vierbien, mathematicalnotation = true, automaticsimplification = true, signature = "+++-")

RicciT := proc (a, b) options operator, arrow; Physics:-SumOverRepeatedIndices(Ricci[mu, nu]*e_[a, `~mu`]*e_[b, `~nu`]) end proc

proc (a, b) options operator, arrow; Physics:-SumOverRepeatedIndices(Physics:-`*`(Physics:-`*`(Physics:-Ricci[mu, nu], Physics:-Tetrads:-e_[a, `~mu`]), Physics:-Tetrads:-e_[b, `~nu`])) end proc

(7)

SlashD := proc (f, a) options operator, arrow; Physics:-SumOverRepeatedIndices(Physics:-D_[mu](f)*e_[a, `~mu`]) end proc

proc (f, a) options operator, arrow; Physics:-SumOverRepeatedIndices(Physics:-`*`(Physics:-D_[mu](f), Physics:-Tetrads:-e_[a, `~mu`])) end proc

(8)

SlashD(H(X), 4) = H(X)[4]

(diff(H(X), zetabar))*Ybar(X)+(diff(H(X), zeta))*Y(X)+diff(H(X), v)-(diff(H(X), u))*Y(X)*Ybar(X) = H(X)[4]

(9)

Gamma := proc (a, b, c) options operator, arrow; -gamma_[a, b, c] end proc

proc (a, b, c) options operator, arrow; Physics:-`*`(Physics:-Tetrads:-gamma_[a, b, c], -1) end proc

(10)

Gamma(1, 4, 4) = 0

-(diff(Ybar(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Ybar(X), zeta))+Ybar(X)*(diff(Ybar(X), zetabar))+diff(Ybar(X), v) = 0

(11)

``

Gamma(2, 4, 4) = 0

-(diff(Y(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Y(X), zeta))+(diff(Y(X), zetabar))*Ybar(X)+diff(Y(X), v) = 0

(12)

``

Gamma(3, 4, 4) = 0

0 = 0

(13)

``

Gamma(4, 4, 4) = 0

0 = 0

(14)

Gamma(4, 1, 1) = 0

-(diff(Ybar(X), zeta))+(diff(Ybar(X), u))*Ybar(X) = 0

(15)

``

Gamma(4, 2, 2) = 0

-(diff(Y(X), zetabar))+(diff(Y(X), u))*Y(X) = 0

(16)

NULL

shearconditions := {-(diff(Y(X), zetabar))+(diff(Y(X), u))*Y(X) = 0, -(diff(Ybar(X), zeta))+(diff(Ybar(X), u))*Ybar(X) = 0, -(diff(Y(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Y(X), zeta))+(diff(Y(X), zetabar))*Ybar(X)+diff(Y(X), v) = 0, -(diff(Ybar(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Ybar(X), zeta))+Ybar(X)*(diff(Ybar(X), zetabar))+diff(Ybar(X), v) = 0}

{-(diff(Y(X), zetabar))+(diff(Y(X), u))*Y(X) = 0, -(diff(Ybar(X), zeta))+(diff(Ybar(X), u))*Ybar(X) = 0, -(diff(Y(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Y(X), zeta))+(diff(Y(X), zetabar))*Ybar(X)+diff(Y(X), v) = 0, -(diff(Ybar(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Ybar(X), zeta))+Ybar(X)*(diff(Ybar(X), zetabar))+diff(Ybar(X), v) = 0}

(17)

simplify(RicciT(1, 2), shearconditions) = 0

H(X)*(diff(diff(Y(X), zeta), zetabar))*Ybar(X)-H(X)*Ybar(X)*Y(X)*(diff(diff(Ybar(X), u), zetabar))-H(X)*Ybar(X)^2*(diff(diff(Y(X), u), zetabar))-H(X)*Y(X)^2*(diff(diff(Ybar(X), u), zeta))-2*H(X)*Y(X)*Ybar(X)*(diff(diff(Y(X), u), zeta))+H(X)*Y(X)^2*Ybar(X)*(diff(diff(Ybar(X), u), u))-H(X)*Y(X)*(diff(diff(Ybar(X), u), v))+H(X)*Y(X)*Ybar(X)^2*(diff(diff(Y(X), u), u))-H(X)*(diff(diff(Y(X), u), v))*Ybar(X)+H(X)*(diff(Ybar(X), zetabar))^2+(-3*H(X)*Y(X)*(diff(Ybar(X), u))-(diff(H(X), u))*Y(X)*Ybar(X)+(diff(H(X), zeta))*Y(X)+(diff(H(X), zetabar))*Ybar(X)+diff(H(X), v))*(diff(Ybar(X), zetabar))+H(X)*(diff(Y(X), zeta))^2+(-4*H(X)*(diff(Y(X), u))*Ybar(X)-(diff(H(X), u))*Y(X)*Ybar(X)+(diff(H(X), zeta))*Y(X)+(diff(H(X), zetabar))*Ybar(X)+diff(H(X), v))*(diff(Y(X), zeta))+2*H(X)*Y(X)^2*(diff(Ybar(X), u))^2-Y(X)*((diff(H(X), zetabar))*Ybar(X)+(diff(H(X), zeta))*Y(X)+diff(H(X), v)-(diff(H(X), u))*Y(X)*Ybar(X))*(diff(Ybar(X), u))+2*(H(X)*(diff(Y(X), u))*Ybar(X)+(1/2)*(diff(H(X), u))*Y(X)*Ybar(X)-(1/2)*(diff(H(X), zeta))*Y(X)-(1/2)*(diff(H(X), zetabar))*Ybar(X)-(1/2)*(diff(H(X), v)))*(diff(Y(X), u))*Ybar(X) = 0

(18)

0 = 0

0 = 0

(19)

The values in the paraenthesis  should substitute H[4]. This sequence works in Maple 18 but not in Maple 2015

 

NULL


Download Question_algsubs_3.27.15.mw

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