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Next: 10. Basic Integral for Up: Classical and Quantum Shell Previous: 8. The FGG-method and

   
9. Hamiltonian for $A_{in} {\buildrel > \over <} 0$, $A_{out} {\buildrel > \over <}0$

For the sake of notational simplicity, let us set GN=1. We start with the expression of the momentum in the case6 Ain > 0 and Aout > 0:

$\displaystyle \frac{P_R}{R}$ = $\displaystyle \tanh ^{-1}
\left(
\frac{
\dot{R}
\left(
\sigma _{in} \beta _{in}...
...
{
\sigma _{in} \sigma _{out}
\beta _{in} \beta _{out}
-
\dot{R} ^{2}
}
\right)$  
  = $\displaystyle \frac{1}{2} \ln \left [
\frac{
\left(
\sigma _{in} \beta _{in}-\d...
...
\dot{R}
\right)
\left(
\sigma _{out} \beta _{out}
-
\dot{R}
\right)
}
\right ]$  
  = $\displaystyle \ln \left [
\frac{
\left(
\sigma _{in} \beta _{in} - \dot{R}
\rig...
...ft(
\sigma _{out} \beta _{out} + \dot{R}
\right) ^{2}
}
\right ] ^{\frac{1}{2}}$  
  = $\displaystyle \ln \left [
\sqrt{\frac{A_{out}}{A_{in}}}
\frac{\vert \sigma _{in...
...n} - \dot{R} \vert}
{\vert \sigma _{out} \beta _{out} - \dot{R} \vert}
\right ]$  
  = $\displaystyle \ln \left [
\sqrt{\frac{A_{out}}{A_{in}}}
\frac{
\left(
\sigma _{...
...
{
\left(
\sigma _{out} \beta _{out} - \dot{R}
\right)
\sigma _{out}
}
\right ]$  
  = $\displaystyle \ln \left [
\sigma _{in} \sigma _{out}
\sqrt{\frac{A_{out}}{A_{in...
...} \beta _{in} - \dot{R}}
{\sigma _{out} \beta _{out} - \dot{R}}\right ]
\quad .$ (111)

Then, enlisting the equalities

\begin{displaymath}e ^{\frac{P_R}{R}}
-
\sigma _{in} \sigma _{out} \sqrt{\frac...
...\beta _{out}}
{\sigma _{out} \beta _{out} - \dot{R}}
\right)
\end{displaymath} (112)


\begin{displaymath}e ^{- \frac{P_R}{R}}
-
\sigma _{in} \sigma _{out} \sqrt{\fr...
...out}}
{\sigma _{out} \beta _{out} + \dot{R}}
\right)
\quad ,
\end{displaymath} (113)

so that
    $\displaystyle 1 +
\frac{A_{out}}{A_{in}} -
2 \sigma _{in} \sigma _{out}
\sqrt{\frac{A_{out}}{A_{in}}} \cosh \left( \frac{P_R}{R} \right)
=$  
    $\displaystyle \
=
\left (
e^{\frac{P_R}{R}}
-
\sigma _{in} \sigma _{out} \sqrt{...
...{P_R}{R}}
-
\sigma _{in} \sigma _{out} \sqrt{\frac{A_{out}}{A_{in}}}
\right )
=$ (114)
    $\displaystyle \qquad \qquad \qquad \qquad \qquad \qquad \qquad
=
\frac{1}{A_{in}}
\left(
\frac{H - \kappa R^{2}}{R}
\right) ^{2}
\quad ,$ (115)

we find the explicit form of the Hamiltonian quoted in the text (Eq.55):

\begin{displaymath}H = \kappa R ^{2}
-
R \left [
A_{in} +
A_{out} -
2 \sigm...
... \left( \frac{P_R}{R} \right)
\right ] ^{\frac{1}{2}}
\quad .
\end{displaymath} (116)

We now repeat the same steps for the case Ain > 0 and Aout < 0. Letting $\bar{A} _{out} = - A_{out}$, we find

$\displaystyle \frac{P_R}{R}$ = $\displaystyle \tanh ^{-1}
\left(
\frac{
\sigma _{in} \sigma _{out}
\beta _{in} ...
...
\left(
\sigma _{in} \beta _{in}
-
\sigma _{out} \beta _{out}
\right)
}
\right)$  
  = $\displaystyle \frac{1}{2} \ln \left [
\frac{
\left(
\sigma _{in} \beta _{in} - ...
...ta _{in}
\right)
\left(
\dot{R} - \sigma _{out} \beta _{out}
\right)
}
\right ]$  
  = $\displaystyle \ln \left [
\frac{
\left(
\sigma _{in} \beta _{in} - \dot{R}
\rig...
...\sigma _{out} \beta _{out} - \dot{R}
\right) ^{2}
}
(-)
\right ] ^{\frac{1}{2}}$  
  = $\displaystyle \ln \left [
\sqrt{\frac{\bar{A} _{out}}{A_{in}}}
\frac{
\left\ver...
...vert
}
{
\left\vert \sigma _{out} \beta _{out} - \dot{R} \right\vert
}
\right ]$  
  = $\displaystyle \ln \left [
\sqrt{\frac{\bar{A} _{out}}{A_{in}}}
\frac{
\left( \s...
... _{in}
}
{
\left( \sigma _{out} \beta _{out} - \dot{R} \right) ( - )
}
\right ]$  
  = $\displaystyle \ln \left [
- \sigma _{in} \sqrt{\frac{\bar{A} _{out}}{A_{in}}}
\...
... \beta _{in} - \dot{R}}
{\sigma _{out} \beta _{out} - \dot{R}}
\right ]
\quad .$ (117)

Enlisting now the equalities

\begin{displaymath}e ^{\frac{P_R}{R}} +
\sigma _{in} \sqrt{\frac{\bar{A} _{out}...
..._{out}}
{\sigma _{out} \beta _{out} - \dot{R}}
\right) ( - )
\end{displaymath} (118)


\begin{displaymath}e ^{- \frac{P_R}{R}} -
\sigma _{in} \sqrt{\frac{\bar{A} _{ou...
...out}}
{\sigma _{out} \beta _{out} + \dot{R}}
\right)
\quad ,
\end{displaymath} (119)

so that
    $\displaystyle 1 -
\frac{\bar{A} _{out}}{A_{in}} -
2 \sigma _{in} \sqrt{\frac{\bar{A} _{out}}{A_{in}}}
\sinh \left( \frac{P_R}{R} \right)
=$  
    $\displaystyle \qquad \qquad
=
\left (
e ^{\frac{P_R}{R}} +
\sigma _{in} \sqrt{\...
...- \frac{P_R}{R}} -
\sigma _{in} \sqrt{\frac{\bar{A} _{out}}{A_{in}}}
\right )
=$ (120)
    $\displaystyle \qquad \qquad \qquad \qquad \qquad \qquad \qquad
=
\frac{1}{A_{in}}
\left(
\frac{H - \left( 4 \pi \rho \right) R^{2}}{R}
\right) ^{2}
\quad ,$ (121)

we find

\begin{displaymath}H = \kappa R ^{2} -
R \left [
A_{in} +
A_{out} -
2 \sigma...
... \left( \frac{P_R}{R} \right)
\right ] ^{\frac{1}{2}}
\quad .
\end{displaymath} (122)

Evidently, we can follow the same procedure in the cases Ain < 0, Aout < 0; Ain < 0, Aout > 0. The corresponding expressions are
$\displaystyle H = \kappa R ^{2} -
R \left [
A_{in} +
A_{out} -
2 \sqrt{A_{in} A_{out}}
\cosh \left( \frac{P_R}{R} \right)
\right ] ^{\frac{1}{2}}$     (123)
$\displaystyle {\rm if}
\quad
A_{in} < 0 \, , \ A_{out} < 0$      


$\displaystyle H = \kappa R ^{2} -
R \left [
A_{in} +
A_{out} -
2 \sigma _{out} \sqrt{- A_{in} A_{out}}
\sinh \left( \frac{P_R}{R} \right)
\right ] ^{\frac{1}{2}}$     (124)
$\displaystyle {\rm if}
\quad
A_{in} <0 \, , \ A_{out} > 0
\quad ,$      

or, in a more compact notation
H = $\displaystyle \kappa R^{2}
-
{\rm Sgn} ( \rho ) R \cdot$  
    $\displaystyle \cdot
\left[\,
A_{in} +
A_{out} -
2 \sigma _{in} \sigma _{out}
\l...
...\vert A_{in} A_{out} \vert}
}
}
\right) ^{\frac{1}{2}}
\right] ^{\frac{1}{2}}
.$ (125)

The Hamiltonian for the shell of dust quoted in Section IV can be derived along the same steps with little change, and one obtains
H = $\displaystyle m
-
{\rm Sgn} ( m ) R \cdot$  
    $\displaystyle \cdot
\left[\,
A_{in} +
A_{out} -
2 \sigma _{in} \sigma _{out}
\l...
...\vert A_{in} A_{out} \vert}
}
}
\right) ^{\frac{1}{2}}
\right] ^{\frac{1}{2}}
.$ (126)


next up previous
Next: 10. Basic Integral for Up: Classical and Quantum Shell Previous: 8. The FGG-method and

Stefano Ansoldi
Department of Theoretical Physics
University of Trieste
TRIESTE - ITALY