Results 51 to 60 of about 13,955 (195)
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
Relativity and Singularities - A Short Introduction for Mathematicians [PDF]
, 2005 We summarize the main ideas of General Relativity and Lorentzian geometry, leading to a proof of the simplest of the celebrated Hawking-Penrose singularity theorems.
Natario, Jose
core +5 more sources
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
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
A Re‐Examination of Foundational Elements of Cosmology
Fortschritte der Physik, Volume 74, Issue 3, March 2026.ABSTRACT This paper undertakes a conceptual re‐examination of several foundational elements of cosmology through the lens of spacetime symmetries. A new derivation of the Friedmann–Lemaître–Robertson–Walker metric is obtained by a careful conceptual examination of rotations and translations on generic manifolds, followed by solving the rotational and ...
Lavinia Heisenberg
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
Normal forms for sub-Lorentzian metrics supported on Engel type distributions
, 2013 We construct normal forms for Lorentzian metrics on Engel distributions under the assumption that abnormal curves are timelike future directed Hamiltonian geodesics.
Grochowski, Marek
core +1 more source
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
wiley +1 more source