H F Dowker et al 2000 Class. Quantum Grav. 17 697 doi:10.1088/0264-9381/17/3/308
Morse index and causal continuity. A criterion for topology change in quantum gravity
H F Dowker
, R S Garcia and S Surya
Studies in 1 + 1 dimensions suggest that causally discontinuous topology-changing spacetimes are suppressed in quantum gravity. Borde and Sorkin have conjectured that causal discontinuities are associated precisely with index 1 or n - 1 Morse points in topology-changing spacetimes built from Morse functions. We establish a weaker form of this conjecture. Namely, if a Morse function f on a compact cobordism has critical points of index 1 or n - 1, then all the Morse geometries associated with f are causally discontinuous, while if f has no critical points of index 1 or n - 1, then there exist associated Morse geometries which are causally continuous.
- PACS
-
04.60.Kz Lower dimensional models; minisuperspace models
04.20.Gz Spacetime topology, causal structure, spinor structure
- MSC
- Subjects
- Dates
-
Issue 3 (7 February 2000)
Received 13 October 1999
-
Morse index and causal continuity. A criterion for topology change in quantum gravity
H F Dowker et al 2000 Class. Quantum Grav. 17 697
-
Digging up the past: modelling resistive surveys
Bob Kibble 2004 Phys. Educ. 39 177
-
Solvable coupled Hamiltonian for a periodic potential
Frank Szmulowicz 2004 Eur. J. Phys. 25 569
-
Design of a light stimulator for fetal and neonatal magnetoencephalography
J D Wilson et al 2009 Physiol. Meas. 30 N1
-
Improvements to the NIST network time protocol servers
Judah Levine 2008 Metrologia 45 S12
-
Cavity ring down spectroscopy experiment for an advanced undergraduate laboratory
T Stacewicz et al 2007 Eur. J. Phys. 28 789
-
Characteristic wave velocities in spherical electromagnetic cloaks
A D Yaghjian et al 2009 New J. Phys. 11 113011
-
Diffraction of a Gaussian beam at a perfectly conducting half-screen
P Hillion 1995 J. Opt. 26 57
-
Noncommutative BTZ black hole and discrete time
B P Dolan et al 2007 Class. Quantum Grav. 24 1647
-
Fast imaging of partially conductive linear cracks using impedance data
Kurt Bryan et al 2006 Inverse Problems 22 1337
Related review articles
What's this?- Loop quantum cosmology: a status report
- Tunnelling methods and Hawking's radiation: achievements and prospects
- Quantitative approaches to information recovery from black holes