The paper by Andrew Strominger proposes a holographic duality relating quantum gravity on de Sitter space ($dS_D$) to conformal field theory (CFT) on a single $(D-1)$-sphere. For $dS_3$, the central charge of the CFT is computed using the asymptotic symmetry group at the future boundary ($\mathcal{I}^+$). The dS/CFT proposal is supported by the computation of correlation functions of a massive scalar field. The dual CFT may be non-unitary and can contain complex conformal weights if there are sufficiently massive stable scalars. The paper also discusses the physical region $\mathcal{O}^-$ of $dS_3$, which can be foliated by asymptotically flat spacelike slices, and the time evolution generated by $\vec{L}_0 + \vec{L}_0$ is dual to scale transformations in the boundary CFT$_2$. The dS/CFT correspondence is extended to higher dimensions, where the bulk quantum gravity on $dS_D$ is holographically dual to a Euclidean CFT on $S^{D-1}$.The paper by Andrew Strominger proposes a holographic duality relating quantum gravity on de Sitter space ($dS_D$) to conformal field theory (CFT) on a single $(D-1)$-sphere. For $dS_3$, the central charge of the CFT is computed using the asymptotic symmetry group at the future boundary ($\mathcal{I}^+$). The dS/CFT proposal is supported by the computation of correlation functions of a massive scalar field. The dual CFT may be non-unitary and can contain complex conformal weights if there are sufficiently massive stable scalars. The paper also discusses the physical region $\mathcal{O}^-$ of $dS_3$, which can be foliated by asymptotically flat spacelike slices, and the time evolution generated by $\vec{L}_0 + \vec{L}_0$ is dual to scale transformations in the boundary CFT$_2$. The dS/CFT correspondence is extended to higher dimensions, where the bulk quantum gravity on $dS_D$ is holographically dual to a Euclidean CFT on $S^{D-1}$.