--- created: 2023-03-14T16:33 updated: 2024-04-13T20:57 aliases: - hyperbolic geometry - hyperbolic - hyperbolic plane - hyperbolic disc - Poincare model - hyperbolic 3-manifolds - hyperbolic curve - hyperbolic curves - hyperbolic surface - hyperbolic surfaces - hyperbolic structures - hyperbolic manifolds --- --- - Tags: - #todo/untagged - Refs: - #todo/add-references - Links: - [lattice](lattice.md) - [orthogonal group](Unsorted/orthogonal%20group.md) --- # hyperbolic geometry As a [symmetric space](symmetric%20space.md): ![](2024-04-13-13.png) ![](2023-04-03-9.png) ![](2023-04-03-10.png) Can realize $$\HH^n = {\Orth_{1, n} \over \Orth_1 \times \Orth_n}.$$ and as a special case $$\HH^1 = {\SL_2(\RR)\over \SO_2}$$ since $\SO^+_{1, 2} \cong \PSL_2(\RR) \implies \Orth_{1, 2}\cong \SL_2(\RR)$. Hyperbolic metrics: ![](attachments/2023-03-14metric.png) Orientation-preserving isometries: $\Isom(\DD) = \PSU_{1, 1}(\CC)$ (contains [Fuchsian groups](Unsorted/Fuchsian%20group.md)) and $\Isom(\HH) = \PSL_2(\RR)$. General isometies: $\PSU_{1, 1}(\CC)\semidirect C_2$, similar to how $\Isom(\EE^2) = \Orth_2(\RR) = \SO_2(\RR)\semidirect C_2$. # hyperbolic curves ![](2023-04-26-3.png) ![](attachments/Pasted%20image%2020220526001811.png) ![](attachments/Pasted%20image%2020220430141323.png) # hyperbolic surface ![](attachments/Pasted%20image%2020220502181322.png)