10,862 research outputs found
The trouble with asymptotically safe inflation
In this paper we investigate the perturbation theory of the asymptotically
safe inflation and we find that all modes of gravitational waves perturbation
become ghosts in order to achieve a large enough number of e-folds. Formally we
can calculate the power spectrum of gravitational waves perturbation, but we
find that it is negative. It indicates that there is serious trouble with the
asymptotically safe inflation.Comment: 13 pages, 1 figur
Practical Distributed Control Synthesis
Classic distributed control problems have an interesting dichotomy: they are
either trivial or undecidable. If we allow the controllers to fully
synchronize, then synthesis is trivial. In this case, controllers can
effectively act as a single controller with complete information, resulting in
a trivial control problem. But when we eliminate communication and restrict the
supervisors to locally available information, the problem becomes undecidable.
In this paper we argue in favor of a middle way. Communication is, in most
applications, expensive, and should hence be minimized. We therefore study a
solution that tries to communicate only scarcely and, while allowing
communication in order to make joint decision, favors local decisions over
joint decisions that require communication.Comment: In Proceedings INFINITY 2011, arXiv:1111.267
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