\begin{figure}[H] \centering % to rescale everything proportionally by a factor n: replace n with a factor, uncomment the line below, uncomment } for closing the scaling command (this can be found in the line right after \end{tikzpicture}) \scalebox{0.48}{ \begin{tikzpicture}
\filldraw[fill=white, draw=white] (0,0) rectangle (8,14);
%true exterior copy of I\draw[black, thick] (4,4) -- (6,2) -- (8,4) -- (6,6) -- (4,4);%label I\node [thick, black] at (6,4) {I};
%true interior copy of II\draw[black, thick] (4,4) -- (6,6) -- (4,8) -- (2,6) -- (4,4);%label II\node [black] at (4,6) {II};
%true interior copy of III\draw[black, thick] (2,6) -- (4,8) -- (2,10) -- (0,8) -- (2,6);%label III\node [black] at (2,8) {III};
%p in III%\draw[fill=black] (3,8) circle [radius=0.05];%\node [below, black] at (3,8) {$p$};
%scri+\node [above, black] at (7.2,5) {$\mathcal{I}^{+}$};
%label EH\node [black] at (5,5) {EH};
%label CH\node [black] at (3,7) {CH};
%gamma in I%\draw[fill=black] (5.5,4) circle [radius=0.05];%\draw[black, thin] (5.5,4) to [out=105,in=270] (6,6);%\node[black] at (6,5) {$\gamma$};
%thin copy of II below\draw[gray, thin, dashed] (4,4) -- (2,2) -- (4,0) -- (6,2); %label II\node [thick, gray] at (4,2) {II};
%thin copy of I below\draw[gray, thin, dashed] (2,2) -- (0,4) -- (2,6);%label I\node [thick, gray] at (2,4) {I};
%thin copy of III above\draw[gray, thin, dashed] (4,8) -- (6,10) -- (8,8) -- (6,6);%label III\node [thick, gray] at (6,8) {III};
%thin copy of II above\draw[gray, thin, dashed] (2,10) -- (4,12) -- (6,10);%label II\node [thick, gray] at (4,10) {II};
%thin copy of I above\draw[gray, thin, dashed] (2,10) -- (0,12) -- (2,14) -- (4,12);%label I\node [thick, gray] at (2,12) {I};
%thin copy of I above\draw[gray, thin, dashed] (6,10) -- (8,12) -- (6,14) -- (4,12);%label I\node [thick, gray] at (6,12) {I};
\end{tikzpicture} % the bracket below is for closing the scaling command: } %\caption{Penrose diagram showing causal structure of a subset of subextremal Kerr spacetime. Region I represent the universe outside the black hole, region II the black hole interior, region III the deep interior. The maximal analytic extension continues infinitely in the manner shown on shaded copies of regions I, II, III. Acausal features of region III are not shown on this diagram. Event horizon is marked with EH, Cauchy horizon with CH, point $p$ and curve $\gamma$ show the Malament-Hogarth property.} \label{fig:kerrdiagramfirst}\end{figure}