Some additions on cosmology

Signed-off-by: Riccardo Finotello <riccardo.finotello@gmail.com>
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2020-10-04 12:09:49 +02:00
parent 5123a92e78
commit 5a7583760e
6 changed files with 1574 additions and 636 deletions

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@@ -6,28 +6,28 @@ In this appendix we show the computation of the parameters of the hypergeometric
In the main text we set
\begin{equation}
D~
\rM_{\vb{\infty}}~
\rM_{\infty}~
D^{-1}
=
e^{-2\pi i \delta_{\vb{\infty}}}\,
\cL(\vb{n}_{\vb{\infty}}),
e^{-2\pi i \delta_{\infty}}\,
\cL(\vec{n}_{\infty}),
\end{equation}
where $\cL(\vb{n}_{\vb{\infty}}) \in \SU{2}$.
where $\cL(\vec{n}_{\infty}) \in \SU{2}$.
The previous equation implies
\begin{equation}
\qty( D\, \rM_{\vb{\infty}}\, D^{-1} )^\dagger
\qty( D\, \rM_{\infty}\, D^{-1} )^\dagger
=
\qty( D\, \rM_{\vb{\infty}}\, D^{-1} )^{-1},
\qty( D\, \rM_{\infty}\, D^{-1} )^{-1},
\end{equation}
which can be rewritten as
\begin{equation}
\widetilde{\rM}_{\vb{\infty}}^{-1}~
\widetilde{\rM}_{\infty}^{-1}~
\cC^{\dagger}\, D^{\dagger}\, D\, \cC
=
\cC^{\dagger}\, D^{\dagger}\, D\, \cC~
\widetilde{\rM}_{\vb{\infty}}^{-1}.
\widetilde{\rM}_{\infty}^{-1}.
\end{equation}
As $\widetilde{\rM}_{\vb{\infty}}$ is a generic diagonal matrix, the previous equation implies that the off-diagonal elements of $\cC^{\dagger}\, D^{\dagger}\, D\, \cC$ must vanish.
As $\widetilde{\rM}_{\infty}$ is a generic diagonal matrix, the previous equation implies that the off-diagonal elements of $\cC^{\dagger}\, D^{\dagger}\, D\, \cC$ must vanish.
We therefore have
\begin{equation}
\begin{split}
@@ -76,71 +76,71 @@ This would then imply
We can finally show in details the computation of the parameters of the basis of hypergeometric functions used in the main text.
The relation between these and the \SU{2} matrices can be computed requiring that the monodromies induced by the choice of the parameters equal the monodromies produced by the rotations of the D-branes.
The monodromy in $\omega_{\bart-1} = 0$ is simpler to compute given that we choose $\cL(\vb{n}_{\vb{0}})$ and $\cR(\widetilde{\vb{m}}_{\vb{0}})$ to be diagonal.
The monodromy in $\omega_{\bart-1} = 0$ is simpler to compute given that we choose $\cL(\vec{n}_{0})$ and $\cR(\widetilde{\vec{m}}_{0})$ to be diagonal.
We impose:
\begin{eqnarray}
\mqty( \dmat{1, e^{-2\pi i c^{(L)}}} )
& = &
e^{-2\pi i \delta_{\vb{0}}^{(L)}}\,
\mqty( \dmat{e^{2\pi i n_{\vb{0}}}, e^{-2\pi i n_{\vb{0}}}} ),
e^{-2\pi i \delta_{0}^{(L)}}\,
\mqty( \dmat{e^{2\pi i n_{0}}, e^{-2\pi i n_{0}}} ),
\\
\mqty( \dmat{1, e^{-2\pi i c^{(R)}}} )
& = &
e^{-2\pi i \delta_{\vb{0}}^{(R)}}\,
\mqty( \dmat{e^{-2\pi i m_{\vb{0}}}, e^{2\pi i m_{\vb{0}}}} ),
e^{-2\pi i \delta_{0}^{(R)}}\,
\mqty( \dmat{e^{-2\pi i m_{0}}, e^{2\pi i m_{0}}} ),
\end{eqnarray}
where $n^3_{\vb{0}} = \norm{\vb{n}_{\vb{0}}} = n_{\vb{0}}$ and $m^3_{\vb{0}} = \norm{\vb{m}_{\vb{0}}} = m_{\vb{0}}$ with $0 \le n_{\vb{0}},\, m_{\vb{0}} < 1$ due to the conventions \eqref{eq:maximal_torus_left} and \eqref{eq:maximal_torus_right}.
where $n^3_{0} = \norm{\vec{n}_{0}} = n_{0}$ and $m^3_{0} = \norm{\vec{m}_{0}} = m_{0}$ with $0 \le n_{0},\, m_{0} < 1$ due to the conventions \eqref{eq:maximal_torus_left} and \eqref{eq:maximal_torus_right}.
We thus have:
\begin{equation}
\begin{split}
\delta_{\vb{0}}^{(L)}
\delta_{0}^{(L)}
& =
n_{\vb{0}} + k_{\delta^{(L)}_{\vb{0}}},
n_{0} + k_{\delta^{(L)}_{0}},
\qquad
k_{\delta^{(L)}_{\vb{0}}} \in \Z,
k_{\delta^{(L)}_{0}} \in \Z,
\\
c^{(L)}
& =
2 n_{\vb{0}} + k_c,
2 n_{0} + k_c,
\qquad
k_c \in \Z.
\end{split}
\label{eq:cL}
\end{equation}
Since the determinant of the right hand side is $e^{-4 \pi i \delta_{\vb{0}}^{(L)}}$, the range of definition of $\delta_{\vb{0}}^{(L)}$ is $\alpha \le \delta_{\vb{0}}^{(L)} \le \alpha + \frac{1}{2}$.
Given that $0 \le n_{\vb{0}} < \frac{1}{2}$ we simply take $\alpha = 0$ and set $\delta_{\vb{0}}^{(L)} = n_{\vb{0}}$.
Since the determinant of the right hand side is $e^{-4 \pi i \delta_{0}^{(L)}}$, the range of definition of $\delta_{0}^{(L)}$ is $\alpha \le \delta_{0}^{(L)} \le \alpha + \frac{1}{2}$.
Given that $0 \le n_{0} < \frac{1}{2}$ we simply take $\alpha = 0$ and set $\delta_{0}^{(L)} = n_{0}$.
Analogous results hold in the right sector.
Furthermore from the third equation in \eqref{eq:parameters_equality_zero} and from the first equation in \eqref{eq:cL} we can restrict:
\begin{equation}
n_{\vb{0}} + m_{\vb{0}} - A \in \Z.
n_{0} + m_{0} - A \in \Z.
\end{equation}
We then need to find $3$ equations to determine $a^{(L)}$, $b^{(L)}$ and $\delta^{(L)}_{\vb{\infty}}$.
We then need to find $3$ equations to determine $a^{(L)}$, $b^{(L)}$ and $\delta^{(L)}_{\infty}$.
After that we then fix the remaining factors in $B$ and $\abs{K^{(L)}}$.
The equations follow from~\eqref{eq:parameters_equality_infty}.
The first two equations for $a^{(L)}$, $b^{(L)}$ and $\delta^{(L)}_{\vb{\infty}}$ follow by considering the trace of~\eqref{eq:parameters_equality_infty}:
The first two equations for $a^{(L)}$, $b^{(L)}$ and $\delta^{(L)}_{\infty}$ follow by considering the trace of~\eqref{eq:parameters_equality_infty}:
\begin{equation}
e^{\pi i ( a^{(L)} + b^{(L)} )} \cos(\pi( a^{(L)} - b^{(L)} ) )
=
e^{-2\pi i \delta^{(L)}_{\infty}} \cos(2\pi n_{\vb{\infty}}),
e^{-2\pi i \delta^{(L)}_{\infty}} \cos(2\pi n_{\infty}),
\end{equation}
which is satisfied by:
\begin{equation}
\begin{split}
\delta^{(L)}_{\vb{\infty}}
\delta^{(L)}_{\infty}
& =
-
\frac{1}{2}(a^{(L)} + b^{(L)})
+
\frac{1}{2} k_{\delta^{(L)}_{\vb{\infty}}},
\frac{1}{2} k_{\delta^{(L)}_{\infty}},
\qquad
k_{\delta_{\vb{\infty}}} \in \Z,
k_{\delta_{\infty}} \in \Z,
\\
a^{(L)} - b^{(L)}
& =
2\, (-1)^{p^{(L)}}\, n_{\vb{\infty}}
2\, (-1)^{p^{(L)}}\, n_{\infty}
+
(-1)^{q^{(L)}}\, k_{\delta^{(L)}_{\vb{\infty}}}
(-1)^{q^{(L)}}\, k_{\delta^{(L)}_{\infty}}
+
2\, k'_{a b},
\qquad
@@ -154,31 +154,31 @@ We therefore have:
\begin{equation}
a^{(L)} - b^{(L)}
=
2\, n_{\vb{\infty}}
2\, n_{\infty}
+
k_{\delta^{(L)}_{\vb{\infty}}}
k_{\delta^{(L)}_{\infty}}
+
2 k_{ab},
\qquad
k_{a b}\in \Z.
\label{eq:aL-bL}
\end{equation}
The allowed values for $k_{\delta^{(L)}_{\vb{\infty}}}$ follow a construction similar to the monodromy around $\omega_{\bart-1} = 0$.
The allowed values for $k_{\delta^{(L)}_{\infty}}$ follow a construction similar to the monodromy around $\omega_{\bart-1} = 0$.
The main difference is given by the fact that $\frac{1}{2}(a^{(L)} + b^{(L)})$ may a priori take values in an interval of width $1$.
As in the previous case we have $\alpha \le \delta_{\vb{\infty}}^{(L)} \le \alpha + \frac{1}{2}$ with $\alpha$ technically arbitrary.
We cannot thus choose a vanishing $k_{\delta^{(L)}_{\vb{\infty}}}$ but we have to consider $k_{\delta^{(L)}_{\infty}} = 0,\, 1$.
As in the previous case we have $\alpha \le \delta_{\infty}^{(L)} \le \alpha + \frac{1}{2}$ with $\alpha$ technically arbitrary.
We cannot thus choose a vanishing $k_{\delta^{(L)}_{\infty}}$ but we have to consider $k_{\delta^{(L)}_{\infty}} = 0,\, 1$.
We find a third relation by considering the entry
\begin{equation}
\Im\qty(
e^{+2\pi i \delta_{\vb{\infty}}^{(L)}}\,
e^{+2\pi i \delta_{\infty}^{(L)}}\,
D^{(L)}\,
\rM_{\vb{\infty}}^{(L)}\,
\rM_{\infty}^{(L)}\,
\qty( D^{(L)} )^{-1}
)_{11}
=
\Im\qty(
\cL(n_{\vb{\infty}})
\cL(n_{\infty})
)_{11}.
\end{equation}
Using
@@ -191,31 +191,31 @@ and the second equation in~\eqref{eq:cL} and~\eqref{eq:aL-bL} leads to:
\begin{equation}
\cos(\pi( a^{(L)} + b^{(L)} - c^{(L)} ))
=
(-1)^{k_c+k_{\delta^{(L)}_{\vb{\infty}}} }\, \cos(2\pi \cA^{(L)}),
(-1)^{k_c+k_{\delta^{(L)}_{\infty}} }\, \cos(2\pi \cA^{(L)}),
\end{equation}
where
\begin{equation}
\cos(2\pi \cA^{(L)})
=
\cos(2\pi n_{\vb{0}})\,
\cos(2\pi n_{\vb{\infty}})
\cos(2\pi n_{0})\,
\cos(2\pi n_{\infty})
-
\sin(2\pi n_{\vb{0}})\,
\sin(2\pi n_{\vb{\infty}})\,
\frac{n_{\vb{\infty}}^3}{n_{\vb{\infty}}}.
\sin(2\pi n_{0})\,
\sin(2\pi n_{\infty})\,
\frac{n_{\infty}^3}{n_{\infty}}.
\label{eq:cos_n1}
\end{equation}
This expression is connected with rotation parameter in the third interaction point $\omega_{\bart+1} = 1$.
In fact $\cos(2\pi \cA^{(L)}) = \cos(2\pi {n}_{\vb{1}})$.
In fact $\cos(2\pi \cA^{(L)}) = \cos(2\pi {n}_{1})$.
We then write
\begin{equation}
a^{(L)} + b^{(L)} - c^{(L)}
=
2\, (-1)^{f^{(L)}}\, n_{\vb{1}}
2\, (-1)^{f^{(L)}}\, n_{1}
+
k_c
+
k_{\delta^{(L)}_{\vb{\infty}}}
k_{\delta^{(L)}_{\infty}}
+
2\, k_{abc},
\qquad
@@ -228,13 +228,13 @@ The request
+
B
-
n_{\vb{0}}
n_{0}
-
m_{\vb{0}}
m_{0}
-
(-1)^{f^{(L)}}\, n_{\vb{1}}
(-1)^{f^{(L)}}\, n_{1}
-
(-1)^{f^{(R)}}\, m_{\vb{1}}
(-1)^{f^{(R)}}\, m_{1}
\in \Z
\end{equation}
finally fixes the $B$ parameter in the third equation of~\eqref{eq:parameters_equality_infty}.
@@ -243,51 +243,51 @@ So far we can summarise the results in
\begin{eqnarray}
a
=
n_{\vb{0}} + (-1)^{f^{(L)}} n_{\vb{1}} + n_{\vb{\infty}} + m_a,
n_{0} + (-1)^{f^{(L)}} n_{1} + n_{\infty} + m_a,
& \qquad &
m_a \in \Z,
\\
b
=
n_{\vb{0}} + (-1)^{f^{(L)}} n_{\vb{1}} - n_{\vb{\infty}} + m_b,
n_{0} + (-1)^{f^{(L)}} n_{1} - n_{\infty} + m_b,
& \qquad &
m_b \in \Z,
\\
c
=
2\, n_{\vb{0}} + m_c,
2\, n_{0} + m_c,
& \qquad &
m_c \in \Z,
\\
\delta_{\vb{0}}^{(L)}
\delta_{0}^{(L)}
=
n_{\vb{0}},
n_{0},
\\
\delta_{\vb{\infty}}^{(L)}
\delta_{\infty}^{(L)}
=
- n_{\vb{0}} - (-1)^{f^{(L)}} n_{\vb{1}} + m_c + 2\, m_\delta,
- n_{0} - (-1)^{f^{(L)}} n_{1} + m_c + 2\, m_\delta,
& \qquad &
m_{\delta} \in \Z,
\\
A
=
n_{\vb{0}} + m_{\vb{0}} + m_A,
n_{0} + m_{0} + m_A,
& \qquad &
m_A \in \Z,
\\
B
=
(-1)^{f^{(L)}}\, n_{\vb{1}} + (-1)^{f^{(R)}}\, m_{\vb{1}} + m_B,
(-1)^{f^{(L)}}\, n_{1} + (-1)^{f^{(R)}}\, m_{1} + m_B,
& \qquad &
m_B \in \Z.
\end{eqnarray}
$K^{(L)}$ is finally determined from
\begin{equation}
\qty( D^{(L)}\, \rM_{\vb{\infty}}\, \qty( D^{(L)} )^{-1} )_{21}
\qty( D^{(L)}\, \rM_{\infty}\, \qty( D^{(L)} )^{-1} )_{21}
=
e^{-2\pi i \delta_{\vb{\infty}}^{(L)}}\,
\qty( \cL(n_{\vb{\infty}}) )_{21},
e^{-2\pi i \delta_{\infty}^{(L)}}\,
\qty( \cL(n_{\infty}) )_{21},
\label{eq:fixing_K_21}
\end{equation}
and get:
@@ -296,9 +296,9 @@ and get:
=
-\frac{(-1)^{m_a + m_b + m_c}}{2 \pi^2}\,
\cG( a^{(L)},\, b^{(L)},\, c^{(L)} )\,
\sin(2 \pi n_{\vb{0}})
\sin(2 \pi n_{\vb{\infty}})
\frac{n^1_{\vb{\infty}} + i\, n^2_{\vb{\infty}}}{n_{\vb{\infty}}},
\sin(2 \pi n_{0})
\sin(2 \pi n_{\infty})
\frac{n^1_{\infty} + i\, n^2_{\infty}}{n_{\infty}},
\label{eq:app_B_K21}
\end{equation}
where $\cG( a,\, b,\, c ) = \gfun{1-a}\, \gfun{1-b}\, \gfun{a+1-c}\, \gfun{b+1-c}$.
@@ -316,16 +316,16 @@ The result is
\cG(1 - a^{(L)},\, 1 - b^{(L)},\, 2 - c^{(L)})\,
\\
& \times
\sin(2 \pi n_{\vb{0}})\,
\sin(2 \pi n_{\vb{\infty}})\,
\frac{n^1_{\vb{\infty}} -i n^2_{\vb{\infty}}}{n_{\vb{\infty}}},
\sin(2 \pi n_{0})\,
\sin(2 \pi n_{\infty})\,
\frac{n^1_{\infty} -i n^2_{\infty}}{n_{\infty}},
\end{split}
\label{eq:app_B_K12}
\end{equation}
where the function $\cG( a,\, b,\, c )$ was defined at the end of the previous section.
Compatibility with~\eqref{eq:app_B_K21} requires
\begin{equation}
\frac{(n^1_{\vb{\infty}})^2 + (n^2_{\vb{\infty}})^2}{n^2_{\vb{\infty}}}
\frac{(n^1_{\infty})^2 + (n^2_{\infty})^2}{n^2_{\infty}}
=
-4 \frac{\sin(\pi a) \sin(\pi(c-a))\sin(\pi b) \sin(\pi(c-b))}
{\sin^2(\pi c) \sin^2(\pi(a-b))}.
@@ -333,7 +333,7 @@ Compatibility with~\eqref{eq:app_B_K21} requires
\end{equation}
We can then rewrite~\eqref{eq:cos_n1} as
\begin{equation}
\frac{(n^3_{\vb{\infty}})^2}{n^2_{\vb{\infty}}}
\frac{(n^3_{\infty})^2}{n^2_{\infty}}
=
\frac{(\cos(\pi (a-b)) \cos(\pi c)- \cos(\pi(a+b-c)))^2}
{\sin^2(\pi c) \sin^2(\pi(a-b))}.
@@ -341,10 +341,10 @@ We can then rewrite~\eqref{eq:cos_n1} as
It is then possible to verify that the sum of the left and right hand sides of~\eqref{eq:n12+n22} and the last equation are equal to $1$.
The same consistency check can also be performed by computing $K^{(L)}$ from
\begin{equation}
\qty( D^{(L)}\, \rM_{\vb{\infty}}\, \qty( D^{(L)} )^{-1} )_{12}
\qty( D^{(L)}\, \rM_{\infty}\, \qty( D^{(L)} )^{-1} )_{12}
=
e^{-2\pi i \delta_{\vb{\infty}}^{(L)}}\,
\qty( \cL(n_{\vb{\infty}}) )_{12},
e^{-2\pi i \delta_{\infty}^{(L)}}\,
\qty( \cL(n_{\infty}) )_{12},
\end{equation}
instead of \eqref{eq:fixing_K_21}.