Cosmology of the Planck era from a renormalization group for quantum gravity

Homogeneous and isotropic cosmologies of the Planck era before the classical Einstein equations become valid are studied taking quantum gravitational effects into account. The cosmological evolution equations are renormalization group improved by including the scale dependence of Newton's constant and of the cosmological constant as it is given by the flow equation of the effective average action for gravity. It is argued that the Planck regime can be treated reliably in this framework because gravity is found to become asymptotically free at short distances. The epoch immediately after the initial singularity of the Universe is described by an attractor solution of the improved equations which is a direct manifestation of an ultraviolet attractive renormalization group fixed point. It is shown that quantum gravity effects in the very early Universe might provide a resolution to the horizon and flatness problems of standard cosmology, and could generate a scale-free spectrum of primordial density fluctuations.

[1]  M. Reuter,et al.  Ultraviolet fixed point and generalized flow equation of quantum gravity , 2001 .

[2]  Reuter.  Effective average action of Chern-Simons field theory. , 1996, Physical review. D, Particles and fields.

[3]  A. Abdel-Rahman.  A critical density cosmological model with varying gravitational and cosmological “constants” , 1990 .

[4]  Phenomenological constraints on a scale-dependent gravitational coupling , 1995, hep-ph/9512431.

[5]  N. Tsamis,et al.  Relaxing the cosmological constant , 1993 .

[6]  M. Reuter.  Renormalization of the topological charge in Yang-Mills theory , 1996 .

[7]  Mass inflation in a rotating charged black hole. , 1995, Physical review. D, Particles and fields.

[8]  C. Wetterich,et al.  Gluon condensation in nonperturbative flow equations , 1997 .

[9]  A. Arbab,et al.  Causal Dissipative Cosmology With Variable G and Λ , 1998 .

[10]  C. Everitt,et al.  Flat FRW models with variableG and Λ , 1992 .

[11]  The dark matter problem and quantum gravity , 1992, gr-qc/9210005.

[12]  A. Beesham.  Variable-G cosmology and creation , 1986 .

[13]  Renormalization group improved black hole spacetimes , 2000, hep-th/0002196.

[14]  S. Odintsov,et al.  Exact renormalization group for O(4) gauged supergravity , 1997 .

[15]  A. Beesham.  Comment on the paper «The cosmological constant (Λ) as a possible primordial link to Einstein’s theory of gravity, the properties of hadronic matter and the problem of creation» , 1986 .

[16]  P. Mazur,et al.  Conformal Invariance and Cosmic Background Radiation , 1996, astro-ph/9611208.

[17]  M. Berman.  Cosmological models with variable gravitational and cosmological “constants” , 1991 .

[18]  C. Wetterich,et al.  Average action for the Higgs model with abelian gauge symmetry , 1993 .

[19]  R. Sisteró.  Cosmology withG and Λ coupling scalars , 1991 .

[20]  Dalvit,et al.  Running coupling constants, Newtonian potential, and nonlocalities in the effective action. , 1994, Physical review. D, Particles and fields.

[21]  Thanu Padmanabhan,et al.  Structure formation in the universe , 1993 .

[22]  A. Barvinsky,et al.  Asymptotic freedom in higher-derivative quantum gravity , 1985 .

[23]  O. Bertolami,et al.  Quantum gravity and the large scale structure of the universe , 1993 .

[24]  Martin Reuter,et al.  Effective average action for gauge theories and exact evolution equations , 1994 .

[25]  Alfio Bonanno,et al.  Quantum gravity effects near the null black hole singularity , 1999 .

[26]  Quantum Liouville field theory as solution of a flow equation , 1996, hep-th/9605039.

[27]  N. Tsamis,et al.  Strong infrared effects in quantum gravity. , 1995 .

[28]  C. Wetterich,et al.  Exact evolution equation for scalar electrodynamics , 1994 .

[29]  Exact renormalization group and running Newtonian coupling in higher-derivative gravity , 1997, hep-th/9705008.

[30]  Wataru Souma,et al.  Non-Trivial Ultraviolet Fixed Point in Quantum Gravity , 1999, hep-th/9907027.

[31]  J. Zinn-Justin,et al.  Gravitation and Quantizations , 1995 .

[32]  Roberto Percacci,et al.  The running gravitational couplings , 1998 .

[33]  A. Beesham,et al.  Causal Viscous Cosmological Models With Variable G and Λ , 2000 .

[34]  Mottola,et al.  Four-dimensional quantum gravity in the conformal sector. , 1992, Physical review. D, Particles and fields.

[35]  Martin Reuter,et al.  Nonperturbative evolution equation for quantum gravity , 1998 .

[36]  E. Fradkin,et al.  Renormalizable asymptotically free quantum theory of gravity , 1982 .

[37]  Berman.  Cosmological models with a variable cosmological term. , 1991, Physical review. D, Particles and fields.

[38]  Prakash Panangaden,et al.  Scaling behavior of interacting quantum fields in curved spacetime , 1982 .

[39]  C. Wetterich,et al.  Running gauge coupling in three dimensions and the electroweak phase transition , 1993 .

[40]  C. Wetterich,et al.  Time evolution of the cosmological “constant” , 1987 .

[41]  A. Starobinsky,et al.  The Case for a positive cosmological Lambda term , 1999, astro-ph/9904398.

[42]  P. Panangaden,et al.  Universality and quantum garvity , 1984 .

[43]  Steven Weinberg,et al.  The Cosmological Constant Problem , 1989 .