Results 41 to 50 of about 13,985 (193)
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
doaj +1 more source
Optimal time travel in the Godel universe
, 2011 Using the theory of optimal rocket trajectories in general relativity, recently developed in arXiv:1105.5235, we present a candidate for the minimum total integrated acceleration closed timelike curve in the Godel universe, and give evidence for its ...
C. Misner +13 more
core +1 more source
Fermat Principle in Finsler Spacetimes
, 2005 It is shown that, on a manifold with a Finsler metric of Lorentzian signature, the lightlike geodesics satisfy the following variational principle. Among all lightlike curves from a point (emission event) to a timelike curve (worldline of receiver), the ...
A.G. Voronovich +20 more
core +2 more sources
Global Hyperbolicity and Completeness [PDF]
, 2002 We prove global hyperbolicity of spacetimes under generic regularity conditions on the metric. We then show that these spacetimes are timelike and null geodesically complete if the gradient of the lapse and the extrinsic curvature $K$ are integrable ...
Geroch +2 more
core +5 more sources
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
openaire +3 more sources
Timelike Bertrand Curves in Semi-Euclidean Space [PDF]
, 2010 In this paper, it is proved that, no special timelike Frenet curve is a Bertrand curve in $\mathbb{E}_2^4$ and also, in $\mathbb{E}_\nu^{n+1}$ $ ({n \ge 3})$, such that the notion of Bertrand curve is definite only in $\mathbb{E}_1^2$ and $\mathbb{E}_1^3$
Ersoy, Soley, Tosun, Murat
core
Fortschritte der Physik, Volume 74, Issue 4, April 2026.Abstract String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single‐field slow‐roll inflation, and that black holes decay. The origins of these statements are elucidated within the string‐theoretical swampland programme.
Kay Lehnert
wiley +1 more source
Recent progress on the notion of global hyperbolicity [PDF]
, 2008 Global hyperbolicity is a central concept in Mathematical Relativity. Here, we review the different approaches to this concept explaining both, classical approaches and recent results.
Bernal +8 more
core +1 more source
A New Padé Approach to Modeling Wormholes in Dekel‐Zhao Dark Matter Halos
Annalen der Physik, Volume 538, Issue 3, March 2026.A matter‐first Padé strategy is introduced to build traversable wormholes from prescribed dark‐matter halos. Rational Padé fits approximately the Dekel–Zhao density and are analytically integrated to obtain a shape function that exactly reproduces the intended matter content, avoiding spurious poles of geometry‐first schemes.
Jonathan Alves Rebouças +4 more
wiley +1 more source
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 ...
openaire +2 more sources