Ghost anomalous dimension in asymptotically safe quantum gravity

We compute the ghost anomalous dimension within the asymptotic-safety scenario for quantum gravity. For a class of covariant gauge fixings and using a functional RG scheme, the anomalous dimension $\eta_c$ is negative, implying an improved UV behavior of ghost fluctuations. At the non-Gaussian UV fi...

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Bibliographische Detailangaben
Hauptverfasser: Eichhorn, Astrid (VerfasserIn) , Gies, Holger (VerfasserIn)
Dokumenttyp: Article (Journal) Kapitel/Artikel
Sprache:Englisch
Veröffentlicht: 2010
In: Arxiv

Online-Zugang:Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1001.5033
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Verfasserangaben:Astrid Eichhorn and Holger Gies
Beschreibung
Zusammenfassung:We compute the ghost anomalous dimension within the asymptotic-safety scenario for quantum gravity. For a class of covariant gauge fixings and using a functional RG scheme, the anomalous dimension $\eta_c$ is negative, implying an improved UV behavior of ghost fluctuations. At the non-Gaussian UV fixed point, we observe a maximum value of $\eta_c\simeq -0.78$ for the Landau-deWitt gauge within the given scheme and truncation. Most importantly, the backreaction of the ghost flow onto the Einstein-Hilbert sector preserves the non-Gaussian fixed point with only mild modifications of the fixed-point values for the gravitational coupling and cosmological constant and the associated critical exponents; also their gauge dependence is slightly reduced. Our results provide further evidence for the asymptotic-safety scenario of quantum gravity.
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