de Sitter space and Holography

IINorth PoleOSouth PoleNorth PoleOSouth PoleII1) An observer in the south pole cannot see anything pastthe diagonal line stretching from the north pole at I − to southpole at I + :O − region .2) O + is the only part that an observer in south pole cansend a signal to.3) The planer coordinate we were talking about covers O −region. (In our notation)4) Changing t → −t the coordinates will cover O + region.5) O − ⋂ O + is the part accessible to the observer on thesouth pole (causal diamond). This is the part with is coveredby static coordinates.22