MG13 - Talk detail |
Participant |
Ma, Yongge | |||||||
Institution |
Beijing Normal University - No.19 Xinjiekouwai Street - Beijing - Beijing - China | |||||||
Session |
QG1 |
Accepted |
Yes |
Order |
3 |
Time |
15:00 - 15:30 | |
Talk |
Oral abstract |
Title |
Loop Quantum Scalar-Tensor Gravity and Cosmology | |||||
Co-authors | ||||||||
Abstract |
The nonperturbative quantization procedure of LQG is successfully extended to a rather general class of 4-dimensional metric theories of gravity, which have received increased attention recently due to motivations coming form cosmology and astrophysics. I will introduce how to reformulate the 4-dimensional scalar-tensor theories of gravity, including $f(R)$ theories, into connection-dynamical formalism with real $SU(2)$ connections as configuration variables. The Hamiltonian formalism marks off two sectors of the theories by the coupling parameter $\omega(\phi)$. In the sector of $\omega(\phi)=-\frac{3}{2}$, the feasible theories are restricted and a new primary constraint generating conformal transformations of spacetime is obtained, while in the other sector of $\omega(\phi)\neq-\frac{3}{2}$, the canonical structure and constraint algebra of the theories are similar to those of general relativity coupled with a scalar field. Both sectors can be cast into connection dynamics by canonical transformations. Through the connection dynamical formalisms, I will further outline the nonpertubative canonical quantization of the scalar-tensor theories by extending the loop quantization scheme of GR. As an example of the cosmological application of loop quantum scalar-tensor theories, I will also introduce the kinematical and dynamical construction of loop quantum Brans-Dicke cosmology. |
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