Results 31 to 40 of about 272 (172)
A comment on Bonnor–Steadman closed timelike curves [PDF]
General Relativity and Gravitation, 2008 The existence and stability closed timelike curves in a Bonnor-Ward spacetime without torsion line singularities is shown by exhibiting particular examples.
Rosa, Valéria M., Letelier, Patricio S.
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Special helices on equiform differential geometry of timelike curves in E_1^4
Cumhuriyet Science Journal, 2021 In this paper, we introduce the moving Frenet frame along the timelike curve in E_1^4 and then Frenet formulas with the equiform parameter in the equiform geometry of the Minkowski space-time.
Fatma Bulut
doaj
Tangent and trinormal spherical images of a time-like curve on the pseudohyperbolic space H30; pp. 216–224 [PDF]
Proceedings of the Estonian Academy of Sciences, 2010 In this work tangent and trinormal spherical images of a time-like curve lying on the pseudohyperbolic space H30 in Minkowski space-time are investigated. We observe that the mentioned spherical images are space-like curves.
Süha Yılmaz +3 more
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Journal of Function Spaces, 2018 In this paper, a class of indefinite hypersurfaces and a class of indefinite surfaces generated by timelike curves located in nullcone in 4-dimensional semi-Euclidean space with index 2 are discussed. Using the unfolding theory in singularity theory, the
Xue Song, Zhigang Wang
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Negative branes, supergroups and the signature of spacetime
Journal of High Energy Physics, 2018 We study the realization of supergroup gauge theories using negative branes in string theory. We show that negative branes are intimately connected with the possibility of timelike compactification and exotic spacetime signatures previously studied by ...
Robbert Dijkgraaf +3 more
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Discriminating Quantum States in the Presence of a Deutschian CTC: A Simulation Analysis
IEEE Transactions on Quantum Engineering, 2022 In an article published in 2009, Brun et al. proved that in the presence of a “Deutschian” closed timelike curve, one can map $K$ distinct nonorthogonal states (hereafter, input set) to the standard orthonormal basis of a $K$-dimensional ...
Leonardo Bacciottini +3 more
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Cauchy problem in spacetimes with closed timelike curves [PDF]
Physical Review D, 1990 The laws of physics might permit the existence, in the real Universe, of closed timelike curves (CTC’s). Macroscopic CTC’s might be a semiclassical consequence of Planck-scale, quantum gravitational, Lorentzian foam, if such foam exists. If CTC’s are permitted, then the semiclassical laws of physics (the laws with gravity classical and other fields ...
Friedman, John +6 more
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Axion Black Hole Solution in Non‐Metricity Gravity
Fortschritte der Physik, Volume 74, Issue 2, February 2026.Abstract A static, spherically symmetric black hole solution in symmetric teleparallel (non‐metricity) gravity sourced by an axion field is constructed. Starting from the modified field equations, exact configurations are obtained characterized by the mass M$M$ and an axion–geometry coupling β$\beta$, with temporal metric function A(r)=1−2Mr+βr$A(r)=1-\
A. Eid, G.G.L. Nashed
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KINKS, ENERGY CONDITIONS AND CLOSED TIMELIKE CURVES [PDF]
International Journal of Modern Physics D, 2000 A link between the possibility of extending a geodesically incomplete kinked spacetime to a spacetime which is geodesically complete and the energy conditions is discussed for the case of a cylindrically-symmetric spacetime kink. It is concluded that neither the strong nor the weak energy condition can be satisfied in the four-dimensional example ...
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Rigidity of anti‐de Sitter (2+1)‐spacetimes with convex boundary near the Fuchsian locus
Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.Abstract We prove that globally hyperbolic compact anti‐de Sitter (2+1)‐spacetimes with a strictly convex spacelike boundary that is either smooth or polyhedral and whose holonomy is close to Fuchsian are determined by the induced metric on the boundary.
Roman Prosanov, Jean‐Marc Schlenker
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