2008/03/31 by Jurjen F. Koksma, Tomislav Prokopec · 1 citation
Physics and Astronomy · #Advanced Differential Geometry Research #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.78.023508
published as Phys.Rev.D78:023508,2008 · 18 pages, 11 figures, published version
openalex publication_date 2008/07/08 · arxiv created 2008/08/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
It has been argued that the quantum (conformal) trace anomaly could potentially provide us with a dynamical explanation of the cosmological constant problem. In this paper, however, we show by means of a semiclassical analysis that the trace anomaly does not affect the cosmological constant. We construct the effective action of the conformal anomaly for flat Friedmann-Lema\\itre-Robertson-Walker spacetimes consisting of local quadratic geometric curvature invariants. Counterterms are thus expected to influence the numerical value of the coefficients in the trace anomaly and we must therefore allow these parameters to vary. We calculate the evolution of the Hubble parameter in quasi-de Sitter spacetime, where we restrict our Hubble parameter to vary slowly in time, and in Friedmann-Lema\\itre-Robertson-Walker spacetimes. We show dynamically that a universe consisting of matter with a constant equation of state, a cosmological constant, and the quantum trace anomaly evolves either to the classical de Sitter attractor or to a quantum trace anomaly driven one. When considering the trace anomaly truncated to quasi-de Sitter spacetime, we find a region in parameter space where the quantum attractor destabilizes. When considering the exact expression of the trace anomaly, a stability analysis shows that whenever the trace anomaly driven attractor is stable, the classical de Sitter attractor is unstable, and vice versa. Semiclassically, the trace anomaly does not affect the classical late time de Sitter attractor, and hence it does not solve the cosmological constant problem.