arXiv:gr-qc/0401102 v1 26 Jan 2004(adsbygoogle = window.adsbygoogle || []).push({});

A New Approach in Quantum Gravity

and its Cosmological Implications

Simone Mercuri

Giovanni Montani

ICRA—International Center for Relativistic Astrophysics

Dipartimento di Fisica (G9),

Universit`

a di Roma, “La Sapienza”,

Piazzale Aldo Moro 5, 00185 Rome, Italy.

e-mail: mercuri@icra.it, montani@icra.it PACS: 04.60.Ds – 98.80.Qc

Abstract

This work concerns a new reformulation of quantum geometrodynamics, which allows to overcome a fundamental ambiguity contained in the canonical approach to quantum gravity: the possibility of performing a (3+1)-slicing of

space-time, when the metric tensor is in a quantum regime. Our formulation provides also a procedure to solve the problems connectedto the so called frozen formalism. In particular we fix the reference frame (i.e. the lapse function and the shift vector) by introducing the so called kinematical action; as a consequence,

the new hamiltonian constraints become parabolic, so arrivingto evolutive

(Schr¨odinger-like) equations for the quantum dynamics.

The kinematical action can be interpreted as the action of a pressure less, but, in general, non geodesic perfect fluid, so in the semi classical limit our theory leads to the dynamics of the gravitational field coupled to a dust which represents the material reference frame we have introduced fixing the slicing. We also investigate thecosmological implications ofthe presence ofthe dust, which,

in the WKB limit of a cosmological problem, makes account for a dark matter component and could play, at present time, a dynamical role.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# A New Approach To Qg

**Physics Forums | Science Articles, Homework Help, Discussion**