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0 votes
1 answer
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Solving the Hamiltonian constraint equation in General Relativity

The constraint equation of general relativity reads as follows \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}}{(2\...
Faber Bosch's user avatar
1 vote
2 answers
39 views

Lagrange Multipliers in ADM formalism

I'm following this lecture notes (https://javierrubioblog.com/wp-content/uploads/2017/08/adm1.pdf) on ADM formalism. After getting action as (see Eq.(5.41)) $$ S=\int\mathrm{d}^4xN\sqrt{\gamma}\left[\...
Photon's user avatar
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1 answer
201 views

What diffeomorphism does the Hamiltonian constraint generate?

Consider the Hamiltonian constraint $\mathcal H(x)$ in the ADM formalism. What diffeomorphism does this generate?
dennis's user avatar
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0 votes
0 answers
79 views

Composition of diffeomorphisms in the ADM formalism?

In the ADM formalism there are 4 constraints: $C_\mu(x)$, which are known as the Hamiltonian and spatial diffeomorphism constraints. In the quantum theory, $C_\mu(x)$ are the generators of ...
dennis's user avatar
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0 votes
1 answer
113 views

Are the Hamiltonian and spatial diffeomorphism constraints satisfied at all times for GR?

The ADM formulation of GR allows the Einstein equations to be recast as an initial value problem. According to Sec 3.3 of these notes the outline of the procedure is as follows: Pick a 3-metric $h_{...
dennis's user avatar
  • 742
2 votes
1 answer
67 views

Topology change and Canonical Formulation?

In the ADM formulation of general relativity it is assumed that the spacetime topology is $\Bbb{R}\times \Sigma$. Suppose I wanted to consider spacetimes that undergo topology change with foliation ...
Joeseph123's user avatar
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