I know two essential points where General Relativity plays a central role in String Theory:(adsbygoogle = window.adsbygoogle || []).push({});

i) definition of the theory using a target spacetime with some Riemannian background metric in the Polyakov action and

ii) recovery of the Einstein field equations as conditions regarding conformal invariance on the world-sheet, i.e. vanishing beta functions.

My question related to (i) is if anybody has ever thought about a construction which is not based on using a Riemann but a Riemann-Cartan manifold?

The question related to (ii) would be if that may result in different consistency conditions, i.e. beta functions, effective / low-energy equations, anomaly cancellation, dimensions and geometry of the background spacetime etc.?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# A String Theory and Einstein-Cartan Gravity

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**