1997/08/05 by Nemanja Kaloper, Keith A. Olive
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Classical mechanics #Conformal map #Cosmology and Gravitation Theories #Einstein #Energy condition #Friedmann–Lemaître–Robertson–Walker metric #General relativity #Geodesic #Geometry #Gravitational singularity #Mathematical physics #Mathematics #Physics #Pulsars and Gravitational Waves Research #Quantum gravity #Quantum mechanics #Scalar (mathematics) #Scalar field #Singularity #Theoretical physics #Universe #astro-ph #f(R) gravity #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.57.811
published as Phys.Rev.D57:811-822,1998 · 23 pages, latex, no figures
arxiv created 1997/08/05 · openalex publication_date 1998/01/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this article, we examine the possibility that there exist special scalar-tensor theories of gravity with completely nonsingular FRW solutions. Our investigation in fact shows that while most probes living in such a universe never see the singularity, gravity waves always do. This is because they couple to both the metric and the scalar field, in a way which effectively forces them to move along null geodesics of the Einstein conformal frame. Since the metric of the Einstein conformal frame is always singular for configurations where matter satisfies the energy conditions, the gravity wave world lines are past inextendable beyond the Einstein frame singularity, and hence the geometry is still incomplete, and thus singular. We conclude that the singularity cannot be entirely removed, but only be made invisible to most, but not all, probes in the theory.