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http://www.arxiv.org/abs/astro-ph/0509163

Do we Observe Quantum Gravity Effects at Galactic Scales?

M. Reuter, H. Weyer

6 pages, 1 figure. Talk given by M.R. at the 21st IAP meeting "Mass Profiles and Shapes of Cosmological Structures", Paris, July 4-9, 2005; to appear in the proceedings

"The nonperturbative renormalization group flow of Quantum Einstein Gravity (QEG) is reviewed. It is argued that there could be strong renormalization effects at large distances, in particular a scale dependent Newton constant, which mimic the presence of dark matter at galactic and cosmological scales."

the version of QEG referred to in this paper is that published by Reuter and Lauscher in 2002

http://www.arxiv.org/abs/hep-th/0110021

Is Quantum Einstein Gravity Nonperturbatively Renormalizable?

O. Lauscher, M. Reuter

18 pages, 3 figures

Class.Quant.Grav. 19 (2002) 483-492

"We find considerable evidence supporting the conjecture that four-dimensional Quantum Einstein Gravity is 'asymptotically safe' in Weinberg's sense. This would mean that the theory is likely to be nonperturbatively renormalizable and thus could be considered a fundamental (rather than merely effective) theory which is mathematically consistent and predictive down to arbitrarily small length scales. For a truncated version of the exact flow equation of the effective average action we establish the existence of a non-Gaussian renormalization group fixed point which is suitable for the construction of a nonperturbative infinite cutoff-limit. The truncation ansatz includes the Einstein-Hilbert action and a higher derivative term."

here is an earlier paper about this, from October 2004. I started a PF thread about it when it came out, but that was a long time ago so I will add the abstract here

http://arxiv.org/abs/hep-th/0410117

Running Newton Constant, Improved Gravitational Actions, and Galaxy Rotation Curves

M. Reuter, H. Weyer

72 pages

PhysRevD.70.124028

"A renormalization group (RG) improvement of the Einstein-Hilbert action is performed which promotes Newton's constant and the cosmological constant to scalar functions on spacetime. They arise from solutions of an exact RG equation by means of a 'cutoff identification' which associates RG scales to the points of spacetime. The resulting modified Einstein equations for spherically symmetric, static spacetimes are derived and analyzed in detail. The modifications of the Newtonian limit due to the RG evolution are obtained for the general case. As an application, the viability of a scenario is investigated where strong quantum effects in the infrared cause Newton's constant to grow at large (astrophysical) distances. For two specific RG trajectories exact vacuum spacetimes modifying the Schwarzschild metric are obtained by means of a solution-generating Weyl transformation. Their possible relevance to the problem of the observed approximately flat galaxy rotation curves is discussed. It is found that a power law running of Newton's constant with a small exponent of the order 10^{-6} would account for their non-Keplerian behavior without having to postulate the presence of any dark matter in the galactic halo."

I see this one has 11 citations, several from other researchers who have taken up the idea

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# Do e Observe Quantum Gravity Effects at Galactic Scales?

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