# Tag Info

3

I think this basically sums up the program for what quantum gravity is. The modern viewpoint is that general relativity (and really just about any quantum field theory) is an effective field theory, and the full theory of quantum gravity must provide an ultraviolet completion. As explained in the Donoghue review suggested by bechira (another good review is ...

2

The webpage you were looking at is run by H. D. Zeh. So if you want to find out what he's talking about the best way to find out is to look up some of his papers, such as: http://arxiv.org/abs/1012.4708. He describes decoherence in quantum gravity in Section 5 of the paper. The basic answer is as follows. The Wheeler-DeWitt equation is time-independent in ...

2

If by asymptotic safety you mean theories that have an interacting UV fixed point, they're a dime a dozen in field theory. Just pick any conformal field theory you like and see if it contains a relevant scalar operator. If so, deform away from the fixed point with that operator. From the viewpoint of wherever it ends up in the IR, the UV is "asymptotically ...

2

About CPT-conservation. If you talk about graviton then you talk about linearized GR. There is theory which tells us that all irreducible representations $\left(\frac{n}{2}, \frac{m}{2} \right) \oplus \left( \frac{m}{2}, \frac{n}{2}\right)$ of the Lorentz group is invariant under $C, P, T$ transformations. The theory of graviton (it may be defined without ...

1

In the particle-physics-oriented part of the theoretical physics community, it was becoming increasingly clear that the Dirac bracket is at most a complicated piece of formalism that isn't able to solve any real physical problems and make theories well-defined or finite or renormalizable etc. So the people who are playing with such tools applied to ...

Only top voted, non community-wiki answers of a minimum length are eligible