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1 vote
1 answer
108 views

What is the determinant of the Wheeler-DeWitt metric tensor constructed from spatial metrics in ADM formalism?

The Hamiltonian constraint of General relativity has the following form \begin{align} \frac{(2\kappa)}{\sqrt{h}}\left(h_{ac} h_{bd} - \frac{1}{D-1} h_{ab} h_{cd} \right)p^{ab} p^{cd} - \frac{\sqrt{h}}{...
Faber Bosch's user avatar
1 vote
1 answer
151 views

Star Radius in the Oppenheimer-Snyder metric using ADM formalism

I'm working with gravitational collapse models, in particular with the Oppenheimer-Snyder model. Short list of the assumptions for those unfamiliar with the model, you have a spherical symmetric ...
LolloBoldo's user avatar
  • 1,611
5 votes
1 answer
141 views

Canonical Commutation relations in gravity

The canonical commutation relations in gravity are sometimes written $$ [\gamma_{ij}(x),\pi^{kl}(y)]=\frac{i\hbar}{2}(\delta_i^k\delta_j^l+\delta_i^l\delta_j^k)\delta^3(x-y),\tag{0} $$ where $\gamma_{...
dennis's user avatar
  • 742
1 vote
0 answers
230 views

How to compute the scalar $^{(4)}R_{\mu\nu} \; ^{(4)}R^{\mu\nu}$ in the ADM formalism in General Relativity?

In the Arnowitt-Deser-Misner (ADM) formalism in General Relativity, the line element takes the form $$ ds^2 = - N^2 dt^2 + \gamma_{ij} ( N^i dt + dx^i) (N^j dt + dx^j) \ , $$ where $\gamma^{ij}$ is ...
QuantumEyedea's user avatar
3 votes
2 answers
453 views

ADM formulation of GR derivative on the 3-metric

In the ADM formalism where the projector is given by ${P^\mu}_\alpha={\delta^\mu}_\alpha+n^\mu{n}_\alpha$ and $n^\alpha$ is a future pointing normal vector to the constant time hypersurface $\Sigma$. ...
James J's user avatar
  • 311
2 votes
2 answers
857 views

Determinant of ADM metric

I am studying inflation and for the calculation of the bispectrum we are using the ADM formalism where the metric is the following form: $$g_{\mu\nu}=\begin{bmatrix}-N^2+N^iN_i&N_i\\N_i&h_{ij}...
James J's user avatar
  • 311
1 vote
0 answers
199 views

How to derive the Hamiltonian of general relativity (ADM formalism without surface terms)?

Given that $$ds^{2} =−N^{2}dt^{2} +h_{ij}(dx^{i} +N^{i}dt)(dx^{j}+N^{j}dt)$$ $$S=\int dt d^{3} x\sqrt{h} N(^{3}R+K_{ij}+K^{ij}-K^{2})$$ where $^{3}R$ is the Ricci scalar of $hij$, $h$ the ...
KatherinD's user avatar