How Do You Write the Neutrino Mixing Matrix Us from Equations 3 and 4?

[SuperStringboy]

Please look at equation 3 and 4 of this paper

http://arxiv.org/abs/0707.2481v1

I am facing problem to write the matrix U^s

Can anybody help me to write the complete matrix?

 

[Hepth]

I think I understand how to write it, but I feel like I'm getting some different minus signs. Basically you want the SO(5) rotation group, and matrices for one direction about another (plane, or whatever its called).

If you look at http://reference.wolfram.com/mathematica/ref/RotationMatrix.html
Under Applications, they show how to generate the matrix form for a rotation in SO[N]. Then you take these and multiply them how they have it in the paper, order obviously matters.

I do:

SO[n_] := Map[RotationMatrix[\[Theta], #] &,    Subsets[Table[UnitVector[n, i], {i, n}], {2}]];
SO5MAP = Map[ MatrixForm, SO[5]];
\[Theta][a_, b_] := Subscript[\[CapitalTheta], a, b]
R12 = SO5MAP[[1]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      1, 2]};
R13 = SO5MAP[[2]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      1, 3]};
R23 = SO5MAP[[5]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      2, 3]};
R14 = SO5MAP[[3]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      1, 4]};
R15 = SO5MAP[[4]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      1, 5]};
R24 = SO5MAP[[6]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      2, 4]};
R25 = SO5MAP[[7]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      2, 5]};
R34 = SO5MAP[[8]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      3, 4]};
R35 = SO5MAP[[9]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      3, 5]};
R45 = SO5MAP[[10]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][      4, 5]};
ROT = R45.(R35.(R34.(R25.(R24.(R15.(R14.(R23.(R13.R12))))))));
ROT /. {Cos[Subscript[\[CapitalTheta], a_, b_]] -> Subscript[c, a, b],     Sin[Subscript[\[CapitalTheta], a_, b_]] -> Subscript[s, a, b]} //   Simplify // MatrixForm

The output looks like

$$\left(<br /> \begin{array}{ccccc}<br /> c_{1,2} c_{1,3} c_{1,4} c_{1,5} & -c_{1,3} c_{1,4} c_{1,5} s_{1,2} & -c_{1,4} c_{1,5} s_{1,3} & -c_{1,5} s_{1,4} & -s_{1,5} \\<br /> c_{2,3} c_{2,4} c_{2,5} s_{1,2}-c_{1,2} \left(c_{2,4} c_{2,5} s_{1,3} s_{2,3}+c_{1,3} \left(c_{2,5} s_{1,4} s_{2,4}+c_{1,4} s_{1,5} s_{2,5}\right)\right) & c_{1,2} c_{2,3} c_{2,4} c_{2,5}+s_{1,2} \left(c_{2,4} c_{2,5} s_{1,3} s_{2,3}+c_{1,3} \left(c_{2,5} s_{1,4} s_{2,4}+c_{1,4} s_{1,5} s_{2,5}\right)\right) & -c_{1,3} c_{2,4} c_{2,5} s_{2,3}+s_{1,3} \left(c_{2,5} s_{1,4} s_{2,4}+c_{1,4} s_{1,5} s_{2,5}\right) & -c_{1,4} c_{2,5} s_{2,4}+s_{1,4} s_{1,5} s_{2,5} & -c_{1,5} s_{2,5} \\<br /> c_{3,5} \left(s_{1,2} \left(c_{3,4} s_{2,3}-c_{2,3} s_{2,4} s_{3,4}\right)+c_{1,2} \left(c_{2,3} c_{3,4} s_{1,3}+\left(-c_{1,3} c_{2,4} s_{1,4}+s_{1,3} s_{2,3} s_{2,4}\right) s_{3,4}\right)\right)-\left(c_{1,2} c_{1,3} c_{1,4} c_{2,5} s_{1,5}+\left(c_{2,3} c_{2,4} s_{1,2}-c_{1,2} \left(c_{2,4} s_{1,3} s_{2,3}+c_{1,3} s_{1,4} s_{2,4}\right)\right) s_{2,5}\right) s_{3,5} & c_{3,5} \left(c_{1,2} c_{3,4} s_{2,3}+s_{1,2} \left(c_{1,3} c_{2,4} s_{1,4}-s_{1,3} s_{2,3} s_{2,4}\right) s_{3,4}-c_{2,3} \left(c_{3,4} s_{1,2} s_{1,3}+c_{1,2} s_{2,4} s_{3,4}\right)\right)-\left(c_{2,4} \left(c_{1,2} c_{2,3}+s_{1,2} s_{1,3} s_{2,3}\right) s_{2,5}+c_{1,3} s_{1,2} \left(-c_{1,4} c_{2,5} s_{1,5}+s_{1,4} s_{2,4} s_{2,5}\right)\right) s_{3,5} & s_{1,3} \left(c_{2,4} c_{3,5} s_{1,4} s_{3,4}+\left(c_{1,4} c_{2,5} s_{1,5}-s_{1,4} s_{2,4} s_{2,5}\right) s_{3,5}\right)+c_{1,3} \left(c_{2,3} c_{3,4} c_{3,5}+s_{2,3} \left(c_{3,5} s_{2,4} s_{3,4}+c_{2,4} s_{2,5} s_{3,5}\right)\right) & c_{2,5} s_{1,4} s_{1,5} s_{3,5}+c_{1,4} \left(-c_{2,4} c_{3,5} s_{3,4}+s_{2,4} s_{2,5} s_{3,5}\right) & -c_{1,5} c_{2,5} s_{3,5} \\<br /> c_{4,5} \left(s_{1,2} \left(c_{2,3} c_{3,4} s_{2,4}+s_{2,3} s_{3,4}\right)+c_{1,2} \left(c_{1,3} c_{2,4} c_{3,4} s_{1,4}+s_{1,3} \left(-c_{3,4} s_{2,3} s_{2,4}+c_{2,3} s_{3,4}\right)\right)\right)-\left(s_{1,2} \left(c_{3,4} s_{2,3} s_{3,5}+c_{2,3} \left(c_{2,4} c_{3,5} s_{2,5}-s_{2,4} s_{3,4} s_{3,5}\right)\right)+c_{1,2} \left(s_{1,3} \left(-c_{2,4} c_{3,5} s_{2,3} s_{2,5}+\left(c_{2,3} c_{3,4}+s_{2,3} s_{2,4} s_{3,4}\right) s_{3,5}\right)+c_{1,3} \left(c_{1,4} c_{2,5} c_{3,5} s_{1,5}-s_{1,4} \left(c_{3,5} s_{2,4} s_{2,5}+c_{2,4} s_{3,4} s_{3,5}\right)\right)\right)\right) s_{4,5} & c_{4,5} \left(c_{3,4} \left(-c_{1,3} c_{2,4} s_{1,2} s_{1,4}+\left(c_{1,2} c_{2,3}+s_{1,2} s_{1,3} s_{2,3}\right) s_{2,4}\right)+\left(-c_{2,3} s_{1,2} s_{1,3}+c_{1,2} s_{2,3}\right) s_{3,4}\right)-\left(c_{3,5} \left(c_{2,4} \left(c_{1,2} c_{2,3}+s_{1,2} s_{1,3} s_{2,3}\right) s_{2,5}+c_{1,3} s_{1,2} \left(-c_{1,4} c_{2,5} s_{1,5}+s_{1,4} s_{2,4} s_{2,5}\right)\right)+\left(c_{1,2} c_{3,4} s_{2,3}+s_{1,2} \left(c_{1,3} c_{2,4} s_{1,4}-s_{1,3} s_{2,3} s_{2,4}\right) s_{3,4}-c_{2,3} \left(c_{3,4} s_{1,2} s_{1,3}+c_{1,2} s_{2,4} s_{3,4}\right)\right) s_{3,5}\right) s_{4,5} & c_{4,5} \left(-c_{3,4} \left(c_{2,4} s_{1,3} s_{1,4}+c_{1,3} s_{2,3} s_{2,4}\right)+c_{1,3} c_{2,3} s_{3,4}\right)-\left(c_{3,5} \left(-c_{1,4} c_{2,5} s_{1,3} s_{1,5}+\left(-c_{1,3} c_{2,4} s_{2,3}+s_{1,3} s_{1,4} s_{2,4}\right) s_{2,5}\right)+\left(c_{2,4} s_{1,3} s_{1,4} s_{3,4}+c_{1,3} \left(c_{2,3} c_{3,4}+s_{2,3} s_{2,4} s_{3,4}\right)\right) s_{3,5}\right) s_{4,5} & c_{2,5} c_{3,5} s_{1,4} s_{1,5} s_{4,5}+c_{1,4} \left(c_{3,5} s_{2,4} s_{2,5} s_{4,5}+c_{2,4} \left(c_{3,4} c_{4,5}+s_{3,4} s_{3,5} s_{4,5}\right)\right) & -c_{1,5} c_{2,5} c_{3,5} s_{4,5} \\<br /> c_{4,5} \left(s_{1,2} \left(c_{3,4} s_{2,3} s_{3,5}+c_{2,3} \left(c_{2,4} c_{3,5} s_{2,5}-s_{2,4} s_{3,4} s_{3,5}\right)\right)+c_{1,2} \left(s_{1,3} \left(-c_{2,4} c_{3,5} s_{2,3} s_{2,5}+\left(c_{2,3} c_{3,4}+s_{2,3} s_{2,4} s_{3,4}\right) s_{3,5}\right)+c_{1,3} \left(c_{1,4} c_{2,5} c_{3,5} s_{1,5}-s_{1,4} \left(c_{3,5} s_{2,4} s_{2,5}+c_{2,4} s_{3,4} s_{3,5}\right)\right)\right)\right)+\left(s_{1,2} \left(c_{2,3} c_{3,4} s_{2,4}+s_{2,3} s_{3,4}\right)+c_{1,2} \left(c_{1,3} c_{2,4} c_{3,4} s_{1,4}+s_{1,3} \left(-c_{3,4} s_{2,3} s_{2,4}+c_{2,3} s_{3,4}\right)\right)\right) s_{4,5} & c_{4,5} \left(c_{3,5} \left(c_{2,4} \left(c_{1,2} c_{2,3}+s_{1,2} s_{1,3} s_{2,3}\right) s_{2,5}+c_{1,3} s_{1,2} \left(-c_{1,4} c_{2,5} s_{1,5}+s_{1,4} s_{2,4} s_{2,5}\right)\right)+\left(c_{1,2} c_{3,4} s_{2,3}+s_{1,2} \left(c_{1,3} c_{2,4} s_{1,4}-s_{1,3} s_{2,3} s_{2,4}\right) s_{3,4}-c_{2,3} \left(c_{3,4} s_{1,2} s_{1,3}+c_{1,2} s_{2,4} s_{3,4}\right)\right) s_{3,5}\right)+\left(c_{3,4} \left(-c_{1,3} c_{2,4} s_{1,2} s_{1,4}+\left(c_{1,2} c_{2,3}+s_{1,2} s_{1,3} s_{2,3}\right) s_{2,4}\right)+\left(-c_{2,3} s_{1,2} s_{1,3}+c_{1,2} s_{2,3}\right) s_{3,4}\right) s_{4,5} & c_{4,5} \left(c_{3,5} \left(-c_{1,4} c_{2,5} s_{1,3} s_{1,5}+\left(-c_{1,3} c_{2,4} s_{2,3}+s_{1,3} s_{1,4} s_{2,4}\right) s_{2,5}\right)+\left(c_{2,4} s_{1,3} s_{1,4} s_{3,4}+c_{1,3} \left(c_{2,3} c_{3,4}+s_{2,3} s_{2,4} s_{3,4}\right)\right) s_{3,5}\right)+\left(-c_{3,4} \left(c_{2,4} s_{1,3} s_{1,4}+c_{1,3} s_{2,3} s_{2,4}\right)+c_{1,3} c_{2,3} s_{3,4}\right) s_{4,5} & -c_{4,5} \left(c_{2,5} c_{3,5} s_{1,4} s_{1,5}+c_{1,4} \left(c_{3,5} s_{2,4} s_{2,5}+c_{2,4} s_{3,4} s_{3,5}\right)\right)+c_{1,4} c_{2,4} c_{3,4} s_{4,5} & c_{1,5} c_{2,5} c_{3,5} c_{4,5}<br /> \end{array}<br /> \right)$$

again, I am not sure where there is a sign difference.

 

[SuperStringboy]

Thanks a loooooooooooot ! :)

 

[Hepth]

Ah actually what you need to do is take the transpose of each of those matrices, then you get what's right:

R12 = Transpose[SO5MAP[[1]]] /. {MatrixForm[x_] :> x} /. { \[Theta] -> \[Theta][1, 2]};

The transpose is what you want, and then apply those in order. The signs will be correct then.

 

[SuperStringboy]

Thanks again. I realized that too. So did not check recently.