Editing Propagator (section)

===Graviton propagator===
The graviton propagator for [[Minkowski space]] in [[general relativity]] is <ref>[https://dspace.library.uu.nl/bitstream/handle/1874/4837/Quantum_theory_of_gravitation.pdf?sequence=2&isAllowed=y Quantum theory of gravitation] library.uu.nl</ref>
<math display="block">G_{\alpha\beta~\mu\nu} = \frac{\mathcal{P}^2_{\alpha\beta~\mu\nu}}{k^2} - \frac{\mathcal{P}^0_s{}_{\alpha\beta~\mu\nu}}{2k^2} = \frac{g_{\alpha\mu} g_{\beta\nu}+ g_{\beta\mu}g_{\alpha\nu}- \frac{2}{D-2} g_{\mu\nu}g_{\alpha\beta}}{k^2},</math>
where <math>D</math> is the number of spacetime dimensions, <math>\mathcal{P}^2</math> is the transverse and traceless [[Spin (physics)#Spin projection quantum number and multiplicity|spin-2 projection operator]] and <math>\mathcal{P}^0_s</math> is a spin-0 scalar [[multiplet]]. 
The graviton propagator for [[Anti-de Sitter space|(Anti) de Sitter space]] is 
<math display="block">G = \frac{\mathcal{P}^2}{2H^2-\Box} + \frac{\mathcal{P}^0_s}{2(\Box+4H^2)},</math>
where <math>H</math> is the [[Hubble's law|Hubble constant]]. Note that upon taking the limit <math>H \to 0</math> and <math>\Box \to -k^2</math>, the AdS propagator reduces to the Minkowski propagator.<ref>{{cite web| url=https://cds.cern.ch/record/378516/files/9902042.pdf |title=Graviton and gauge boson propagators in AdSd+1}}</ref>