caa a22 4500 445386304 CHVBK 20180317143033.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10714-011-1243-1 doi (NATIONALLICENCE)springer-10.1007/s10714-011-1243-1 Stachel John Center for Einstein Studies, Boston University, 02215, Boston, MA, USA aut Conformal and projective structures in general relativity [Elektronische Daten] [John Stachel] It is proposed that compatible conformal and projective structures be taken as the basic space-time structures in general relativity, with the symmetry group restricted to unimodular diffeomorphisms. Models of classical massless fields, such as the Maxwell field, interact directly with the conformal structure; while classical bodies composed of massive particles, such as solids and fluids, interact directly with the projective structure. It is suggested that this difference is the classical limit of the respective quantum-gravitational interactions, which should reflect the differing approaches to the quantization of fields and particles when gravity is neglected. Models of general relativity based on compatible conformal and projective structures should be the basis for the exploration of ideal measurement procedures, both classical and quantum. Springer Science+Business Media, LLC, 2011 General relativity nationallicence Conformal structure nationallicence Projective structure nationallicence Quantum gravity nationallicence General Relativity and Gravitation Springer US; http://www.springer-ny.com 43/12(2011-12-01), 3399-3409 0001-7701 43:12<3399 2011 43 10714 https://doi.org/10.1007/s10714-011-1243-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10714-011-1243-1 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Stachel John Center for Einstein Studies, Boston University, 02215, Boston, MA, USA aut NATIONALLICENCE 773 0- General Relativity and Gravitation Springer US; http://www.springer-ny.com 43/12(2011-12-01), 3399-3409 0001-7701 43:12<3399 2011 43 10714 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer