منابع مشابه
Computability of Fraïssé limits
Fräıssé studied countable structures S through analysis of the age of S, i.e., the set of all finitely generated substructures of S. We investigate the effectiveness of his analysis, considering effectively presented lists of finitely generated structures and asking when such a list is the age of a computable structure. We focus particularly on the Fräıssé limit. We also show that degree spectr...
متن کاملLimits of Computability or Why
In Chapter 3 we discovered that there exist different infinite sizes. For instance, the number of real numbers is a larger infinity than the number of natural numbers. An infinite set is exactly as large as N if one can number the elements of A as the first one, the second one, the third one, etc. Here we aim to show that computing tasks exist that cannot be solved by any algorithm. The idea of...
متن کاملJamming nonlocal quantum correlations.
We present a possible scheme to tamper with non-local quantum correlations in a way that is consistent with relativistic causality, but goes beyond quantum mechanics. A non-local “jamming” mechanism, operating within a certain space-time window, would not violate relativistic causality and would not lead to contradictory causal loops. The results presented in this Letter do not depend on any mo...
متن کاملChapter 4 Limits of Computability or Why
In Chapter 3 we discovered that there exist different infinite sizes. For instance, the number of real numbers is a larger infinity than the number of natural numbers. An infinite set is exactly as large as N if one can number the elements of A as the first one, the second one, the third one, etc. Here we aim to show that computing tasks exist that cannot be solved by any algorithm. The idea of...
متن کاملOptimal measurements for nonlocal correlations
A problem in quantum information theory is to find the experimental setup that maximizes the nonlocality of correlations with respect to some suitable measure such as the violation of Bell inequalities. The latter has however some drawbacks. First and foremost it is unfeasible to determine the whole set of Bell inequalities already for a few measurements and thus unfeasible to find the experime...
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: Physical Review A
سال: 2012
ISSN: 1050-2947,1094-1622
DOI: 10.1103/physreva.86.042109