# Tagged Questions

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In a recent paper on CFT entanglement entropy, I want to understand the defintion of a certain partition function. They consider a metric space $S^1 \times \mathbb{H}^{d-1}_q$ with metric: $$... 1answer 39 views ### Homogeneity and isotropy of stress energy tensor Given the energy momentum tensor in E&M: T_{\mu\nu} = -F_{\mu\alpha} g^{\alpha \beta} F_{\beta \nu} +\frac{1}{4} g_{\mu \nu} F_{\sigma \alpha} g^{\alpha \beta} F_{\beta \rho} g^{\rho \sigma} I ... 1answer 71 views ### Tensors in special relativity [duplicate] I'm trying to understand tensors, but I've come across the following question: Let T^{\mu\nu} by a (2,0) tensor. Give the definitions of T_\mu^{\,\nu}, T_{\mu\nu}, and ... 1answer 147 views ### Stress-energy tensor explicitly in terms of the metric tensor I am trying to write the Einstein field equations$$R_{\mu\nu}-\frac{1}{2}g_{\mu\nu} R=\frac{8\pi G}{c^4}T_{\mu\nu} in such a way that the Ricci curvature tensor $R_{\mu\nu}$ and scalar curvature ...
In field theory, the energy momentum defined as the functional derivative wrt the metric $T_{\mu\nu}=\frac{2}{\sqrt{-g}}\frac{\delta S}{\delta g^{\mu\nu}}$ (up to a sign depending on ...
### Einstein tensor in Friedmann equations : where is the missing $c^2$?
I would like to demonstrate the several forms of the Friedmann equations WITH the $c^2$ factors. Everything is fine ... apart that I have a missing $c^2$ factor somewhere. In all the following $\rho$ ...