Differenze
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dinamica_cosmologica [16/07/2015 08:18] – [E ora dateci gli occhiali del fisico!] Roberto Puzzanghera | dinamica_cosmologica [06/10/2020 07:34] – Roberto Puzzanghera | ||
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Linea 7: | Linea 7: | ||
\end{equation} | \end{equation} | ||
- | Quindi se ad esempio $z=4$ l' | + | Quindi se ad esempio $z=4$ l' |
===== Doveroso maniavantismo iniziale ===== | ===== Doveroso maniavantismo iniziale ===== | ||
Linea 68: | Linea 68: | ||
\begin{equation} | \begin{equation} | ||
\label{2} | \label{2} | ||
+ | \tag{2} | ||
\ddot r = -\dfrac{4}{3}\pi G\rho ~ r | \ddot r = -\dfrac{4}{3}\pi G\rho ~ r | ||
\end{equation} | \end{equation} | ||
Linea 74: | Linea 75: | ||
\begin{equation} | \begin{equation} | ||
+ | \tag{3} | ||
\label{3} | \label{3} | ||
r=R ~\theta | r=R ~\theta | ||
Linea 91: | Linea 93: | ||
\begin{equation} | \begin{equation} | ||
+ | \tag{4} | ||
\label{4} | \label{4} | ||
\ddot R = -\dfrac{4}{3}\pi G\rho ~ R | \ddot R = -\dfrac{4}{3}\pi G\rho ~ R | ||
Linea 105: | Linea 108: | ||
\begin{equation} | \begin{equation} | ||
\label{5} | \label{5} | ||
+ | \tag{5} | ||
\frac{\rho}{\rho_0} = \frac{R^3_0}{R^3} | \frac{\rho}{\rho_0} = \frac{R^3_0}{R^3} | ||
\end{equation} | \end{equation} | ||
Linea 112: | Linea 116: | ||
\begin{equation} | \begin{equation} | ||
\label{6} | \label{6} | ||
+ | \tag{6} | ||
\ddot R = -\frac{4}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^2} | \ddot R = -\frac{4}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^2} | ||
\end{equation} | \end{equation} | ||
Linea 131: | Linea 136: | ||
\begin{equation} | \begin{equation} | ||
\label{7} | \label{7} | ||
+ | \tag{7} | ||
\dot R \ddot R = -\frac{4}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^2} \dot R | \dot R \ddot R = -\frac{4}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^2} \dot R | ||
\end{equation} | \end{equation} | ||
Linea 142: | Linea 148: | ||
\begin{equation} | \begin{equation} | ||
\label{8} | \label{8} | ||
+ | \tag{8} | ||
\dot R \ddot R ~dt = -\frac{4}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^2} ~dR | \dot R \ddot R ~dt = -\frac{4}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^2} ~dR | ||
\end{equation} | \end{equation} | ||
Linea 155: | Linea 162: | ||
\begin{equation} | \begin{equation} | ||
\label{9} | \label{9} | ||
+ | \tag{9} | ||
\int \dot R ~d\dot R = -\frac{4}{3} \pi G \rho_0 R^3_0 \int \frac{1}{R^2} ~dR | \int \dot R ~d\dot R = -\frac{4}{3} \pi G \rho_0 R^3_0 \int \frac{1}{R^2} ~dR | ||
\end{equation} | \end{equation} | ||
Linea 162: | Linea 170: | ||
\begin{equation} | \begin{equation} | ||
\label{10} | \label{10} | ||
+ | \tag{10} | ||
\dot R^2 = \frac{8}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R} + cost | \dot R^2 = \frac{8}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R} + cost | ||
\end{equation} | \end{equation} | ||
Linea 171: | Linea 180: | ||
\begin{equation} | \begin{equation} | ||
\label{11} | \label{11} | ||
+ | \tag{11} | ||
\begin{cases} | \begin{cases} | ||
k=0 \ \ \mbox{spazio euclideo piatto} \\ | k=0 \ \ \mbox{spazio euclideo piatto} \\ | ||
Linea 182: | Linea 192: | ||
\begin{equation} | \begin{equation} | ||
\label{12} | \label{12} | ||
+ | \tag{12} | ||
\dot R^2 = \frac{8}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R} - kc^2 | \dot R^2 = \frac{8}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R} - kc^2 | ||
\end{equation} | \end{equation} | ||
Linea 191: | Linea 202: | ||
\begin{equation} | \begin{equation} | ||
\label{H} | \label{H} | ||
+ | \tag{H} | ||
H = \frac{\dot R}{R} | H = \frac{\dot R}{R} | ||
\end{equation} | \end{equation} | ||
Linea 198: | Linea 210: | ||
\begin{equation} | \begin{equation} | ||
\label{13} | \label{13} | ||
+ | \tag{13} | ||
H^2 = \frac{\dot R^2}{R^2} = \frac{8}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^3} - \frac{kc^2}{R^2} | H^2 = \frac{\dot R^2}{R^2} = \frac{8}{3} \pi G \rho_0 R^3_0 \cdot \frac{1}{R^3} - \frac{kc^2}{R^2} | ||
\end{equation} | \end{equation} | ||
Linea 205: | Linea 218: | ||
\begin{equation} | \begin{equation} | ||
\label{14} | \label{14} | ||
+ | \tag{14} | ||
H^2_0 = \frac{8}{3} \pi G \rho_0 - \frac{kc^2}{R^2_0} | H^2_0 = \frac{8}{3} \pi G \rho_0 - \frac{kc^2}{R^2_0} | ||
\end{equation} | \end{equation} | ||
Linea 212: | Linea 226: | ||
\begin{equation} | \begin{equation} | ||
\label{15} | \label{15} | ||
+ | \tag{15} | ||
1 = \frac{\rho_0}{3H^2_0/ | 1 = \frac{\rho_0}{3H^2_0/ | ||
\end{equation} | \end{equation} | ||
Linea 219: | Linea 234: | ||
\begin{equation} | \begin{equation} | ||
\label{16} | \label{16} | ||
+ | \tag{16} | ||
\rho_c = 3H^2_0/8\pi G | \rho_c = 3H^2_0/8\pi G | ||
\end{equation} | \end{equation} | ||
Linea 226: | Linea 242: | ||
\begin{equation} | \begin{equation} | ||
\label{17} | \label{17} | ||
+ | \tag{17} | ||
\Omega = \frac{\rho_0}{\rho_c} | \Omega = \frac{\rho_0}{\rho_c} | ||
\end{equation} | \end{equation} | ||
Linea 233: | Linea 250: | ||
\begin{equation} | \begin{equation} | ||
\label{18} | \label{18} | ||
+ | \tag{18} | ||
1 = \Omega - \frac{kc^2}{R^2_0 H^2_0} | 1 = \Omega - \frac{kc^2}{R^2_0 H^2_0} | ||
\end{equation} | \end{equation} | ||
Linea 240: | Linea 258: | ||
\begin{equation} | \begin{equation} | ||
\label{19} | \label{19} | ||
+ | \tag{19} | ||
k = \dfrac{R^2_0 H^2_0}{c^2} (\Omega -1) | k = \dfrac{R^2_0 H^2_0}{c^2} (\Omega -1) | ||
\end{equation} | \end{equation} | ||
Linea 267: | Linea 286: | ||
\begin{equation} | \begin{equation} | ||
\label{22} | \label{22} | ||
+ | \tag{22} | ||
\dot R^2 = H^2_0 R^2_0\left(\Omega\frac{R_0}{R}+1-\Omega \right) | \dot R^2 = H^2_0 R^2_0\left(\Omega\frac{R_0}{R}+1-\Omega \right) | ||
\end{equation} | \end{equation} | ||
Linea 274: | Linea 294: | ||
\begin{equation} | \begin{equation} | ||
\label{23} | \label{23} | ||
+ | \tag{23} | ||
\dot R^2 = H^2_0 R^2_0(1-\Omega) | \dot R^2 = H^2_0 R^2_0(1-\Omega) | ||
\end{equation} | \end{equation} | ||
Linea 285: | Linea 306: | ||
\begin{equation} | \begin{equation} | ||
\label{24} | \label{24} | ||
+ | \tag{24} | ||
\dot R^2 = \frac{H^2_0 R^3_0}{R} | \dot R^2 = \frac{H^2_0 R^3_0}{R} | ||
\end{equation} | \end{equation} | ||
Linea 300: | Linea 322: | ||
\begin{equation} | \begin{equation} | ||
\label{25} | \label{25} | ||
+ | \tag{25} | ||
\int_0^R \sqrt{R}~dR = H_0 \sqrt{R^3_0} \int_0^t dt \\ | \int_0^R \sqrt{R}~dR = H_0 \sqrt{R^3_0} \int_0^t dt \\ | ||
\implies | \implies | ||
Linea 326: | Linea 349: | ||
\begin{equation} | \begin{equation} | ||
\label{rho_f} | \label{rho_f} | ||
+ | \tag{fho_f} | ||
\rho_f = n\epsilon | \rho_f = n\epsilon | ||
\end{equation} | \end{equation} | ||
Linea 333: | Linea 357: | ||
\begin{equation} | \begin{equation} | ||
\label{n} | \label{n} | ||
+ | \tag{n} | ||
n \propto \frac{1}{R^3} | n \propto \frac{1}{R^3} | ||
\end{equation} | \end{equation} | ||
Linea 356: | Linea 381: | ||
\begin{equation} | \begin{equation} | ||
\label{eps} | \label{eps} | ||
+ | \tag{eps} | ||
\epsilon \propto \frac{1}{R} | \epsilon \propto \frac{1}{R} | ||
\end{equation} | \end{equation} | ||
Linea 363: | Linea 389: | ||
\begin{equation} | \begin{equation} | ||
\label{30} | \label{30} | ||
+ | \tag{30} | ||
\rho_f \propto \frac{1}{R^4} | \rho_f \propto \frac{1}{R^4} | ||
\end{equation} | \end{equation} | ||
Linea 370: | Linea 397: | ||
\begin{equation} | \begin{equation} | ||
\label{31} | \label{31} | ||
+ | \tag{31} | ||
\rho_m \propto \frac{1}{R^3} | \rho_m \propto \frac{1}{R^3} | ||
\end{equation} | \end{equation} | ||
Linea 387: | Linea 415: | ||
\begin{equation} | \begin{equation} | ||
\label{32} | \label{32} | ||
+ | \tag{32} | ||
\epsilon = kT | \epsilon = kT | ||
\end{equation} | \end{equation} | ||
Linea 396: | Linea 425: | ||
\begin{equation} | \begin{equation} | ||
\label{33} | \label{33} | ||
+ | \tag{33} | ||
T \propto \frac{1}{R} | T \propto \frac{1}{R} | ||
\end{equation} | \end{equation} |