158 research outputs found
Simultaneous dense and nondense orbits for commuting maps
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.We show that, for two commuting automorphisms of the torus and for two elements of the Cartan action on compact higher rank homogeneous spaces, many points have drastically different orbit structures for the two maps. Specifically, using measure rigidity, we show that the set of points that have dense orbit under one map and nondense orbit under the second has full Hausdorff dimension.V. B. acknowledges support received from the National Science Foundation via Grant DMS-1162073
M. E. acknowledges support by the SNF (200021-152819).
J. T. acknowledges the research leading to these results has received funding from the European Research Council under the European Unionâs Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement n. 291147
Simultaneous dense and nondense orbits for commuting maps
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.We show that, for two commuting automorphisms of the torus and for two elements of the Cartan action on compact higher rank homogeneous spaces, many points have drastically different orbit structures for the two maps. Specifically, using measure rigidity, we show that the set of points that have dense orbit under one map and nondense orbit under the second has full Hausdorff dimension.V. B. acknowledges support received from the National Science Foundation via Grant DMS-1162073
M. E. acknowledges support by the SNF (200021-152819).
J. T. acknowledges the research leading to these results has received funding from the European Research Council under the European Unionâs Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement n. 291147
Tropical polyhedra are equivalent to mean payoff games
We show that several decision problems originating from max-plus or tropical
convexity are equivalent to zero-sum two player game problems. In particular,
we set up an equivalence between the external representation of tropical convex
sets and zero-sum stochastic games, in which tropical polyhedra correspond to
deterministic games with finite action spaces. Then, we show that the winning
initial positions can be determined from the associated tropical polyhedron. We
obtain as a corollary a game theoretical proof of the fact that the tropical
rank of a matrix, defined as the maximal size of a submatrix for which the
optimal assignment problem has a unique solution, coincides with the maximal
number of rows (or columns) of the matrix which are linearly independent in the
tropical sense. Our proofs rely on techniques from non-linear Perron-Frobenius
theory.Comment: 28 pages, 5 figures; v2: updated references, added background
materials and illustrations; v3: minor improvements, references update
The MobyDick Project: A Mobile Heterogeneous All-IP Architecture
Proceedings of Advanced Technologies, Applications and Market Strategies for 3G (ATAMS 2001). Cracow, Poland: 17-20 June, 2001.This paper presents the current stage of an IP-based architecture for heterogeneous environments, covering UMTS-like W-CDMA wireless access technology, wireless and wired LANs, that is being developed under the aegis of the IST Moby Dick project. This architecture treats all transmission capabilities as basic physical and data-link layers, and attempts to replace all higher-level tasks by IP-based strategies.
The proposed architecture incorporates aspects of mobile-IPv6, fast handover, AAA-control, and Quality of Service. The architecture allows for an optimised control on the radio link layer resources. The Moby dick architecture is currently under refinement for implementation on field trials. The services planned for trials are data transfer and voice-over-IP.Publicad
Almost Sure Frequency Independence of the Dimension of the Spectrum of Sturmian Hamiltonians
We consider the spectrum of discrete Schr\"odinger operators with Sturmian
potentials and show that for sufficiently large coupling, its Hausdorff
dimension and its upper box counting dimension are the same for Lebesgue almost
every value of the frequency.Comment: 12 pages, to appear in Commun. Math. Phy
Partner orbits and action differences on compact factors of the hyperbolic plane. Part I: Sieber-Richter pairs
Physicists have argued that periodic orbit bunching leads to universal
spectral fluctuations for chaotic quantum systems. To establish a more detailed
mathematical understanding of this fact, it is first necessary to look more
closely at the classical side of the problem and determine orbit pairs
consisting of orbits which have similar actions. In this paper we specialize to
the geodesic flow on compact factors of the hyperbolic plane as a classical
chaotic system. We prove the existence of a periodic partner orbit for a given
periodic orbit which has a small-angle self-crossing in configuration space
which is a `2-encounter'; such configurations are called `Sieber-Richter pairs'
in the physics literature. Furthermore, we derive an estimate for the action
difference of the partners. In the second part of this paper [13], an inductive
argument is provided to deal with higher-order encounters.Comment: to appear on Nonlinearit
Spherical averages in the space of marked lattices
A marked lattice is a -dimensional Euclidean lattice, where each lattice
point is assigned a mark via a given random field on . We prove
that, if the field is strongly mixing with a faster-than-logarithmic rate, then
for every given lattice and almost every marking, large spheres become
equidistributed in the space of marked lattices. A key aspect of our study is
that the space of marked lattices is not a homogeneous space, but rather a
non-trivial fiber bundle over such a space. As an application, we prove that
the free path length in a crystal with random defects has a limiting
distribution in the Boltzmann-Grad limit
VirtuWind: Virtual and programmable industrial network prototype deployed in operational wind park.
With anticipated exponential growth of connected devices, future industrial networks require an open solutions architecture facilitated by standards and a strong ecosystem. Such solutions should also deal with range of quality of service requirements imposed by industrial networks. Preserving strict quality of service is particularly challenging when services pass across domains of multiple provides. VirtuWind aims to develop and demonstrate a Software Defined Networking and Network Function Virtualization ecosystem, based on an open, modular and secure framework to address stringent requirements of the industrial networks. A prototype of the framework for intra-domain and inter-domain scenarios will be showcased in real Wind Parks, as a representative use case of industrial networks. This paper details this vision and explains steps forward
Rational approximation and arithmetic progressions
A reasonably complete theory of the approximation of an irrational by
rational fractions whose numerators and denominators lie in prescribed
arithmetic progressions is developed in this paper. Results are both, on the
one hand, from a metrical and a non-metrical point of view and, on the other
hand, from an asymptotic and also a uniform point of view. The principal
novelty is a Khintchine type theorem for uniform approximation in this context.
Some applications of this theory are also discussed
A Survey of Differentiated Services Proposals for the Internet
Abstract TR/1998/020 Technical Report SSC/1998/020 Authors: Constant Gbaguidi, Hans J. Einsiedler, Paul Hurley, Werner Almesberger and Jean-Pierre Hubaux Date: Title: A Survey of Differentiated Services Proposals for the Internet Abstract Differentiated services are a suitable solution to Quality of Service (QoS) provisioning in the Internet while the number of users keeps growing. The solution is suitable, because it scales well with increasing number of network users and it does not alter the current Internet paradigm much. In this article, we review the state of the art in this ĂnewĂ area, and compare some of the main existing differentiated services architectures. We outline the common solutions across these architectures, thus paving the road to a unified architecture. Lastly, we mention the issues that have not been thoroughly addressed yet
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