منابع مشابه
Stability of Closed Timelike Geodesics
The existence and stability under linear perturbations of closed timelike geodesics (CTG) in Bonnor-Ward spacetime is studied in some detail. Regions where the CTG exist and are linearly stable are exhibited. In 1949 Gödel found a solution to the Einstein field equation with nonzero cosmological constant that admits closed timelike curves (CTC) [1]. It could be argued that the Gödel solution is...
متن کاملClosed Timelike Curves
In this paper, we explore the possibility that closed timelike curves might be allowed by the laws of physics. A closed timelike curve is perhaps the closest thing to time travel that general relativity allows. We will begin our discussing just what closed timelike curves are, and in what kinds of contexts they were first shown to appear. We then explore how one might actually travel on a close...
متن کاملComputability Theory of Closed Timelike Curves
We ask, and answer, the question of what’s computable by Turing machines equipped with time travel into the past: that is, closed timelike curves or CTCs (with no bound on their size). We focus on a model for CTCs due to Deutsch, which imposes a probabilistic consistency condition to avoid grandfather paradoxes. Our main result is that computers with CTCs can solve exactly the problems that are...
متن کاملClosed timelike Curves in relativistic Computation
In this paper, we investigate the possibility of using closed timelike curves (CTCs) in relativistic hypercomputation. We introduce a wormhole based hypercomputation scenario which is free from the common worries, such as the blueshift problem. We also discuss the physical reasonability of our scenario, and why we cannot simply ignore the possibility of the existence of spacetimes containing CTCs.
متن کاملLoop Products and Closed Geodesics
The critical points of the length function on the free loop space Λ(M) of a compact Riemannian manifold M are the closed geodesics on M. The length function gives a filtration of the homology of Λ(M) and we show that the Chas-Sullivan product Hi(Λ)×Hj(Λ) ∗ Hi+j−n(Λ) is compatible with this filtration. We obtain a very simple expression for the associated graded homology ring GrH∗(Λ(M)) when all...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Transactions of the American Mathematical Society
سال: 1984
ISSN: 0002-9947
DOI: 10.2307/1999486