caa a22 4500 445386509 CHVBK 20180317143033.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s10714-010-1088-z doi (NATIONALLICENCE)springer-10.1007/s10714-010-1088-z Mannheim Philip Department of Physics, University of Connecticut, 06269, Storrs, CT, USA aut Comprehensive solution to the cosmological constant, zero-point energy, and quantum gravity problems [Elektronische Daten] [Philip Mannheim] We present a solution to the cosmological constant, the zero-point energy, and the quantum gravity problems within a single comprehensive framework. We show that in quantum theories of gravity in which the zero-point energy density of the gravitational field is well-defined, the cosmological constant and zero-point energy problems solve each other by mutual cancellation between the cosmological constant and the matter and gravitational field zero-point energy densities. Because of this cancellation, regulation of the matter field zero-point energy density is not needed, and thus does not cause any trace anomaly to arise. We exhibit our results in two theories of gravity that are well-defined quantum-mechanically. Both of these theories are locally conformal invariant, quantum Einstein gravity in two dimensions and Weyl-tensor-based quantum conformal gravity in four dimensions (a fourth-order derivative quantum theory of the type that Bender and Mannheim have recently shown to be ghost-free and unitary). Central to our approach is the requirement that any and all departures of the geometry from Minkowski are to be brought about by quantum mechanics alone. Consequently, there have to be no fundamental classical fields, and all mass scales have to be generated by dynamical condensates. In such a situation the trace of the matter field energy-momentum tensor is zero, a constraint that obliges its cosmological constant and zero-point contributions to cancel each other identically, no matter how large they might be. In our approach quantization of the gravitational field is caused by its coupling to quantized matter fields, with the gravitational field not needing any independent quantization of its own. With there being no a priori classical curvature, one does not have to make it compatible with quantization. Springer Science+Business Media, LLC, 2010 Quantum gravity nationallicence Zero-point energy nationallicence Cosmological constant problem nationallicence Conformal gravity nationallicence General Relativity and Gravitation Springer US; http://www.springer-ny.com 43/3(2011-03-01), 703-750 0001-7701 43:3<703 2011 43 10714 https://doi.org/10.1007/s10714-010-1088-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10714-010-1088-z text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Mannheim Philip Department of Physics, University of Connecticut, 06269, Storrs, CT, USA aut NATIONALLICENCE 773 0- General Relativity and Gravitation Springer US; http://www.springer-ny.com 43/3(2011-03-01), 703-750 0001-7701 43:3<703 2011 43 10714 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer