Stable quantum systems in anti-de Sitter space: Causality, independence and spectral properties

If a state is passive for uniformly accelerated observers in n-dimensional anti-de Sitter space-time (i.e. cannot be used by them to operate a perpetuum mobile), they will (a) register a universal value of the Unruh temperature, (b) discover a PCT symmetry, and (c) find that observables in complementary wedge-shaped regions necessarily commute with each other in this state. The stability properties of such a passive state induce a "geodesic causal structure" on AdS and concommitant locality relations. It is shown that observables in these complementary wedge-shaped regions fulfill strong additional independence conditions. In two-dimensional AdS these even suffice to enable the derivation of a nontrivial, local, covariant net indexed by bounded spacetime regions. All these results are model-independent and hold in any theory which is compatible with a weak notion of space-time localization. Examples are provided of models satisfying the hypotheses of these theorems.Comment: 27 pages, 1 figure: dedicated to Jacques Bros on the occasion of his 70th birthday. Revised version: typos corrected; as to appear in J. Math. Phy

Existence and Warr Neutrality for Matching Equilibria in a Public Good Economy: An Aggregative Game Approach

Using the aggregative game approach as developed by Cornes and Hartley (2003, 2007) this paper analyzes the conditions under which matching mechanisms in a public good economy lead to interior matching equilibria in which all agents make strictly positive flat contributions to the public good. In particular we show that the distribution of income among the agents is a crucial determinant for the existence of interior matching equilibria. In addition, we explore which matching mechanisms show Warr neutrality and how the size of the economy affects the possibility of implementing a certain type of Pareto optimal solutions through matching.

Local Quantum Observables in the Anti-deSitter - Conformal QFT Correspondence

Quantum field theory on d+1-dimensional anti-deSitter space-time admits a re-interpretation as a quantum field theory with conformal symmetry on d-dimensional Minkowski space-time. This conjecture originally emerged from string theory considerations. Here, it is proven in a general framework by an explicit identification between the local observables of the two corresponding theories.Comment: Letter based on hep-th/9905179, 4 pages, 1 figur

Block SOR for Kronecker structured representations

Cataloged from PDF version of article.The Kronecker structure of a hierarchical Markovian model (HMM) induces nested block partitionings in the transition matrix of its underlying Markov chain. This paper shows how sparse real Schur factors of certain diagonal blocks of a given partitioning induced by the Kronecker structure can be constructed from smaller component matrices and their real Schur factors. Furthermore, it shows how the column approximate minimum degree (COLAMD) ordering algorithm can be used to reduce fill-in of the remaining diagonal blocks that are sparse LU factorized. Combining these ideas, the paper proposes three-level block successive over-relaxation (BSOR) as a competitive steady state solver for HMMs. Finally, on a set of numerical experiments it demonstrates how these ideas reduce storage required by the factors of the diagonal blocks and improve solution time compared to an all LU factorization implementation of the BSOR solver. © 2004 Elsevier Inc. All rights reserved

Building passports and material inventories – concepts, trends, job sharing

The real estate industry is motivated to contribute to a more sustainable built environment. To meet future sustainability goals, building owners and other decision makers rely on high-quality building-related data. On the one hand, possibilities to collect, access and exchange data improve constantly due to developments in information technology. On the other hand, the task to manage data as a growing and versatile resource becomes more difficult. To overcome resulting challenges, the use of building passports, that can serve as a life cycle data repository for single buildings, can be very useful. The importance of building passports is more and more recognised within the industry, but there is an ongoing discussion about their original function. For this reason, the contribution firstly explains the origins of building passports and how the concept has evolved over time. Furthermore, the following research questions are addressed: (1) What are the main goals, functions and requirements of building passports? (2) Which current developments are related to building passports and how do specific concepts differ? (3) How can a job-sharing with other instruments like material passports be realised and what are the benefits? The research focuses on the situation in Germany considering developments on EU level

The second law of thermodynamics, TCP, and Einstein causality in anti-de Sitter space-time

If the vacuum is passive for uniformly accelerated observers in anti-de Sitter space-time (i.e. cannot be used by them to operate a "perpetuum mobile"), they will (a) register a universal value of the Hawking-Unruh temperature, (b) discover a TCP symmetry, and (c) find that observables in complementary wedge-shaped regions are commensurable (local) in the vacuum state. These results are model independent and hold in any theory which is compatible with some weak notion of space-time localization.Comment: 8 pages, slightly improved results, minor changes in the expository part, new title; to appear in "Classical and Quantum Gravity

Turbulent thermal diffusion of aerosols in geophysics and laboratory experiments

We discuss a new phenomenon of turbulent thermal diffusion associated with turbulent transport of aerosols in the atmosphere and in laboratory experiments. The essence of this phenomenon is the appearance of a nondiffusive mean flux of particles in the direction of the mean heat flux, which results in the formation of large-scale inhomogeneities in the spatial distribution of aerosols that accumulate in regions of minimum mean temperature of the surrounding fluid. This effect of turbulent thermal diffusion was detected experimentally. In experiments turbulence was generated by two oscillating grids in two directions of the imposed vertical mean temperature gradient. We used Particle Image Velocimetry to determine the turbulent velocity field, and an Image Processing Technique based on an analysis of the intensity of Mie scattering to determine the spatial distribution of aerosols. Analysis of the intensity of laser light Mie scattering by aerosols showed that aerosols accumulate in the vicinity of the minimum mean temperature due to the effect of turbulent thermal diffusion. Geophysical applications of the obtained results are discussed.Comment: 9 pages, 6 figures, revtex

Towards a construction of inclusive collision cross-sections in the massless Nelson model

The conventional approach to the infrared problem in perturbative quantum electrodynamics relies on the concept of inclusive collision cross-sections. A non-perturbative variant of this notion was introduced in algebraic quantum field theory. Relying on these insights, we take first steps towards a non-perturbative construction of inclusive collision cross-sections in the massless Nelson model. We show that our proposal is consistent with the standard scattering theory in the absence of the infrared problem and discuss its status in the infrared-singular case.Comment: 23 pages, LaTeX. As appeared in Ann. Henri Poincar\'

Convenient synthesis and purification of [Bu<inf>4</inf>N] <inf>2</inf>[Ru(4-carboxy-4-carboxylate-2,2′-bipyridine) <inf>2</inf>(NCS)<inf>2</inf>]: A landmark DSC Dye

We present here a convenient synthesis of the landmark dye-sensitized solar cell dye [Bu4N]2[Ru(4-carboxy-4-carboxylate-2,2?- bipyridine)2(NCS)2] (N719). Key to this synthetic procedure is the protection of the carboxyl functionalities with iso-butyl ester groups. This strategy allows the use of silica chromatography to remove the less efficient S-bound isomers and significantly reduces the time and difficulty of the synthesis. © CSIRO 2008