scholarly journals Singularities in globally hyperbolic space-time

1975 ◽  
Vol 41 (1) ◽  
pp. 65-78 ◽  
Author(s):  
C. J. S. Clarke
Keyword(s):  
Hyperbolic Space ◽  
Space Time ◽  
Globally Hyperbolic

scholarly journals HOMOTOPY OF POSETS, NET-COHOMOLOGY AND SUPERSELECTION SECTORS IN GLOBALLY HYPERBOLIC SPACE-TIMES

2005 ◽  
Vol 17 (09) ◽  
pp. 1021-1070 ◽  
Author(s):  
GIUSEPPE RUZZI
Keyword(s):  
Hyperbolic Space ◽  
Space Time ◽  
Fundamental Groups ◽  
Mathematical Framework ◽  
Permutation Symmetry ◽  
Index Set ◽  
Globally Hyperbolic ◽  
Underlying Space ◽  
Local Observables ◽  
Suitable Change

We study sharply localized sectors, known as sectors of DHR-type, of a net of local observables, in arbitrary globally hyperbolic space-times with dimension ≥ 3. We show that these sectors define, as it happens in Minkowski space, a C*-category in which the charge structure manifests itself by the existence of a tensor product, a permutation symmetry and a conjugation. The mathematical framework is that of the net-cohomology of posets according to J. E. Roberts. The net of local observables is indexed by a poset formed by a basis for the topology of the space-time ordered under inclusion. The category of sectors, is equivalent to the category of 1-cocycles of the poset with values in the net. We succeed in analyzing the structure of this category because we show how topological properties of the space-time are encoded in the poset used as index set: the first homotopy group of a poset is introduced and it is shown that the fundamental group of the poset and one of the underlying space-time are isomorphic; any 1-cocycle defines a unitary representation of these fundamental groups. Another important result is the invariance of the net-cohomology under a suitable change of index set of the net.

Orthomodular lattice in Lorentzian globally hyperbolic space-time

2017 ◽  
Vol 79 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Wojciech Cegła ◽  
Bernard Jancewicz ◽  
Jan Florek
Keyword(s):  
Hyperbolic Space ◽  
Orthomodular Lattice ◽  
Space Time ◽  
Globally Hyperbolic

Cauchy surfaces in a globally hyperbolic space‐time

1988 ◽  
Vol 29 (3) ◽  
pp. 578-579 ◽  
Author(s):  
Jan Dieckmann
Keyword(s):  
Hyperbolic Space ◽  
Space Time ◽  
Globally Hyperbolic

scholarly journals CAUSALLY PATHOLOGICAL SPACE–TIMES ARE PHYSICALLY RELEVANT

2005 ◽  
Vol 14 (12) ◽  
pp. 2227-2231 ◽  
Author(s):  
VERONIKA E. HUBENY ◽  
MUKUND RANGAMANI ◽  
SIMON F. ROSS
Keyword(s):  
String Theory ◽  
Hyperbolic Space ◽  
Space Time ◽  
Globally Hyperbolic ◽  
Causal Condition

We argue that in the context of string theory, the usual restriction to globally hyperbolic space–times should be considerably relaxed. We exhibit an example of a space–time which only satisfies the causal condition, and so is arbitrarily close to admitting closed causal curves, but which has a well-behaved dual description, free of paradoxes.

Black hole physics in globally hyperbolic space-times

Pramana ◽  
1982 ◽  
Vol 18 (5) ◽  
pp. 385-396 ◽  
Author(s):  
P S Joshi ◽  
J V Narlikar
Keyword(s):  
Black Hole ◽  
Hyperbolic Space ◽  
Black Hole Physics ◽  
Globally Hyperbolic

scholarly journals Cauchy problem on non-globally hyperbolic space-times

2008 ◽  
Vol 157 (3) ◽  
pp. 1646-1654 ◽  
Author(s):  
I. Ya. Aref’eva ◽  
T. Ishiwatari ◽  
I. V. Volovich
Keyword(s):  
Cauchy Problem ◽  
Hyperbolic Space ◽  
Globally Hyperbolic

scholarly journals Interpretations of cosmological spectral shifts

Open Physics ◽  
2013 ◽  
Vol 11 (3) ◽  
Author(s):  
Dag Østvang
Keyword(s):  
Hyperbolic Space ◽  
Spectral Shift ◽  
Space Time ◽  
Flat Connection ◽  
Closed Space ◽  
Spectral Shifts

AbstractIt is shown that for Robertson-Walker models with flat or closed space sections, all of the cosmological spectral shift can be attributed to the non-flat connection (and thus indirectly to space-time curvature). For Robertson-Walker models with hyperbolic space sections, it is shown that cosmological spectral shifts uniquely split up into “kinematic” and “gravitational” parts provided that distances are small. For large distances no such unique split-up exists in general. A number of common, but incorrect assertions found in the literature regarding interpretations of cosmological spectral shifts, is pointed out.

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