Classical world arising out of quantum physics under the restriction of coarse-grained measurements

Conceptually different from the decoherence program, we present a novel theoretical approach to macroscopic realism and classical physics within quantum theory. It focuses on the limits of observability of quantum effects of macroscopic objects, i.e., on the required precision of our measurement apparatuses such that quantum phenomena can still be observed. First, we demonstrate that for unrestricted measurement accuracy no classical description is possible for arbitrarily large systems. Then we show for a certain time evolution that under coarse-grained measurements not only macrorealism but even the classical Newtonian laws emerge out of the Schroedinger equation and the projection postulate.Comment: 4 pages, 1 figure, second revised and published versio

The conditions for quantum violation of macroscopic realism

Why do we not experience a violation of macroscopic realism in every-day life? Normally, no violation can be seen either because of decoherence or the restriction of coarse-grained measurements, transforming the time evolution of any quantum state into a classical time evolution of a statistical mixture. We find the sufficient condition for these classical evolutions for spin systems under coarse-grained measurements. Then we demonstrate that there exist "non-classical" Hamiltonians whose time evolution cannot be understood classically, although at every instant of time the quantum spin state appears as a classical mixture. We suggest that such Hamiltonians are unlikely to be realized in nature because of their high computational complexity.Comment: 4 pages, 2 figures, revised version, journal reference adde

Darmstadt Definition of Sustainable Investments

Sustainable investments cannot focus on profit maximization alone, they also have to contribute to the future of mankind in terms of ecological and social-cultural challenges. How to apply this definition for financial investments is a broadly discussed topic for asset-managers with regard to the many implications on future developments. Many tend to think that investments are sufficiently sustainable if they comply with the particular ideas the investor has about social, ethical or environmental concerns. To provide a deeper and broader definition about sustainable investments, the project Ethical-Ecological Rating initiated an expert workshop on behalf of the German Forum Sustainable Investments and the Corporate Responsibility Interface Center. The workshop's theme was: Definition and understanding of sustainable investments. Experts from several sectors, banks, investors, and other participants with economic or social background attended the workshop. The result is the Darmstadt Definition of Sustainable Investments. The experts involved intend to clarify the understanding of sustainable investments inorder to provide a more profound and stringent insight for actors in economy, society, politics, and administration. For both, the public and notably the investors, it is demonstrated that sustainable investments are one key for a more sustainable economy.Geldanlagen sind nicht schon dann nachhaltig, wenn sie fortlaufend gute Erträge bringen; sie müssen auch in ökologischer und sozial-kultureller Hinsicht zur Zukunftsfähigkeit der Menschheit beitragen. Wann diese Bedingung erfüllt ist, darüber besteht besonders bei den Managern von Anlagefonds Unsicherheit. Verbreitet ist die Neigung, Anlageformen schon dann mit dem Gütezeichen Nachhaltige Geldanlage zu versehen, wenn sie nur in einzelnen Bereichen - sozial, religiös, ökologisch - den Wertvorstellungen der jeweiligen Anleger entsprechen. Um hier Begriffssicherheit zu schaffen, hat die Projektgruppe Ethisch-Ökologisches Rating auf Anregung des Forums Nachhaltige Geldanlagen und des Vereins Ethisch orientierte Investoren (CRIC e.V.) in Darmstadt einen Expertenworkshop zum Thema Begriff und Verständnis nachhaltiger Geldanlagen veranstaltet. In der Expertengruppe haben Vertreter von Unternehmen unterschiedlicher Branchen, von Banken, von Investoren, aus der Wissenschaft und der Zivilgesellschaft mitgewirkt. Das Ergebnis ist die Darmstädter Definition Nachhaltiger Geldanlagen: Nach Meinung aller Experten, die an der Erarbeitung der Darmstädter Definition mitgewirkt haben, soll sie dazu dienen, dem Begriff und Verständnis von Nachhaltigkeit in Wirtschaft, Gesellschaft, Politik und Verwaltung mehr Klarheit und Stringenz zu verschaffen. So kann in der Öffentlichkeit und ganz besonders bei Investoren das Bewusstsein gestärkt werden, dass nachhaltige Geldanlagen ein Schlüssel für die Förderung einer zukunftsfähigen Wirtschaft sind

Far-off-resonant wave interaction in one-dimensional photonic crystals with quadratic nonlinearity

We extend a recently developed Hamiltonian formalism for nonlinear wave interaction processes in spatially periodic dielectric structures to the far-off-resonant regime, and investigate numerically the three-wave resonance conditions in a one-dimensional optical medium with $\chi^{(2)}$ nonlinearity. In particular, we demonstrate that the cascading of nonresonant wave interaction processes generates an effective $\chi^{(3)}$ nonlinear response in these systems. We obtain the corresponding coupling coefficients through appropriate normal form transformations that formally lead to the Zakharov equation for spatially periodic optical media.Comment: 14 pages, 4 figure

Action language processing in Parkinson’s disease: Characterization of neuro-oscillatory dynamics and linguistic performance

Human language capacity is based on temporally coordinated neural activity across distributed brain regions. Although the left hemispheric perisylvian cortex constitutes the core region of language processing, a network of additional sites is further involved. For example, in the healthy brain, semantic access to action concepts has been associated with increased neural activity within frontal motor areas. These findings are complemented by studies demonstrating impaired action language processing in patients with Parkinson's disease, a condition leading to impaired motor control. Therefore, both lines of inquiry suggest an involvement of sensorimotor brain regions in the semantic access to action concepts. However, as the neural underpinnings of the putative action language deficit in Parkinson's disease are unknown, the contribution of motor areas to this phenomenon remains unresolved. This study therefore aimed at resolving this question by characterizing neurophysiological and behavioral correlates of action language processing in patients with Parkinson's disease. For this purpose, two experiments were carried out. The goal of Experiment 1 was to compile and validate a data set of action pictures for the German language. This part of the study aimed at identifying psycholinguistic variables affecting naming latency in a picture naming task, allowing the selection of matched sets of stimuli in prospective studies. Experiment 2 built upon these data and employed an action naming task and high-density electroencephalography to characterize oscillatory patterns during action language production in both healthy participants and patients with Parkinson's disease. Specifically, this part of the study examined whether action language processing is accompanied with aberrant oscillatory patterns in the mu and beta frequency range over motor cortical areas in the parkinsonian state. Furthermore, the influence of dopaminergic medication on these patterns was assessed. In Experiment 1, a total of 283 freely available action pictures could be assembled and characterized. The principal variables affecting naming latency describe the agreement in responses across subjects: Less homogeneous response distributions were associated with longer reaction times. Furthermore, word frequency as well as the motor content of the pictures and responses were significant predictors of naming latency. Experiment 2 could not replicate the behavioral action naming deficit in patients with Parkinson's disease when compared to healthy participants. However, differential neurophysiological correlates of action naming were observed. In contrast to healthy subjects, a transient episode of beta hypersynchronization was present over central to frontal electrodes in Parkinson's disease patients off medication within 300 to 700 ms after stimulus presentation. Cluster-based permutation tests confirmed this difference in oscillatory power and by reconstructing the sources of neural activity it could be localized to the left pre- and postcentral cortex and to the right anterior temporal lobe. Furthermore, subsequent mu power suppression (from 800 ms onwards) was stronger in patients with Parkinson's disease than in healthy controls. The associations between psycholinguistic variables and naming latency found in Experiment 1 were largely consistent with action naming normative studies carried out in other languages. The data set of 283 action pictures may therefore constitute a valuable resource for future psycholinguistic investigations of action language processing. In Experiment 2, behavioral results were not in keeping with a specific action language deficit in patients with Parkinson's disease, which stands in contrast to prior studies. However, patients included in this study attained a higher level of education as those examined in earlier reports, potentially compensating the hypothesized deficit. On the neurophysiological level though, exaggerated beta power in Parkinson's disease patients showed a spatiotemporal pattern which may reflect aberrant semantic access to action concepts grounded in the motor system: Differential neural activity was partly observed during a previously established time frame for semantic processing and located to brain regions that have been associated with access to action concepts, including the sensorimotor cortex. In conclusion, this study established a methodological basis for further psycholinguistic studies on action language processing by validating a normative action picture data set for the German language. By applying this data set in an action naming task and recording high density electroencephalography in Parkinson's disease patients and healthy controls, neurophysiological correlates of action language processing were examined. While behavioral results were not in keeping with a hypothesized action naming deficit, differential oscillatory activity in the beta frequency range suggests a contribution of the motor system to altered semantic processing of action concepts in patients with Parkinson's disease

A Cryptographic Moving-Knife Cake-Cutting Protocol

This paper proposes a cake-cutting protocol using cryptography when the cake is a heterogeneous good that is represented by an interval on a real line. Although the Dubins-Spanier moving-knife protocol with one knife achieves simple fairness, all players must execute the protocol synchronously. Thus, the protocol cannot be executed on asynchronous networks such as the Internet. We show that the moving-knife protocol can be executed asynchronously by a discrete protocol using a secure auction protocol. The number of cuts is n-1 where n is the number of players, which is the minimum.Comment: In Proceedings IWIGP 2012, arXiv:1202.422

Pseudo Identities Based on Fingerprint Characteristics

This paper presents the integrated project TURBINE which is funded under the EU 7th research framework programme. This research is a multi-disciplinary effort on privacy enhancing technology, combining innovative developments in cryptography and fingerprint recognition. The objective of this project is to provide a breakthrough in electronic authentication for various applications in the physical world and on the Internet. On the one hand it will provide secure identity verification thanks to fingerprint recognition. On the other hand it will reliably protect the biometric data through advanced cryptography technology. In concrete terms, it will provide the assurance that (i) the data used for the authentication, generated from the fingerprint, cannot be used to restore the original fingerprint sample, (ii) the individual will be able to create different "pseudo-identities" for different applications with the same fingerprint, whilst ensuring that these different identities (and hence the related personal data) cannot be linked to each other, and (iii) the individual is enabled to revoke an biometric identifier (pseudo-identity) for a given application in case it should not be used anymore

Improved reservoir quality assessment by evaluating illite grain coatings, quartz cementation, and compaction – Case study from the Buntsandstein, Upper Rhine Graben, Germany

Reservoir quality (RQ) in the Buntsandstein of the Upper Rhine Graben is in the center of attention as it is a possible target formation for geothermal energy production and hydrocarbon exploration surrounding existing fields. An understanding of properties affecting reservoir quality of the target lithology is still fairly poor and the success of accurately targeting high RQ intervals is limited. This is due to the fact, that the effect of compaction and the interplay between enhanced chemical compaction (i.e. pressure dissolution of quartz grains), illitic contact coatings and quartz cementation in the lithology has been underestimated. The understanding and quantification of controlling factors on reservoir qualities in fluvio-eolian sedimentary rocks, deposited in a (semi-)arid climate has been improved in recent years and this case study highlights the benefits of detailed petrographic analyses in understanding diagenetic and compactional processes in this lithology. This is especially relevant in the observation of grain coating clay minerals, whose effect depends on their specific location, i.e. either at grain contacts between quartz grains (GTG coating) or at the interface between detrital quartz grains and the intergranular volume (GTI coating). Illitic GTI coatings affect syntaxial quartz overgrowth precipitation, as precipitation sites are locally blocked. The negative correlation between the grain coating coverage and quartz cement volumes support these findings across multiple sample sets, and they may locally preserve intergranular porosity. Illitic GTG coatings on the other hand enhance chemical compaction (i.e. pressure dissolution) and will reduce the IGV. The negative correlation between these two properties again underlines the negative effect of this process on reservoir properties. Studied samples from a deep Buntsandstein well in the central URG show low reservoir quality due to either intense quartz cementation (0.7–31.7%) or a high degree of mechanical and chemical compaction (IGV: 2.3–38.0%). Higher illitic GTG and GTI coating coverages play a substantial role in controlling reservoir quality development, as demonstrated by comparing data from other fluvio-eolian lithologies (Triassic Buntsandstein and Permian Rotliegendes) to results of this study. In relation to their respective burial histories, higher illitic GTI coating coverages always correlate with smaller syntaxial quartz cement volumes. Similarly, higher illitic GTG coating coverages always correlate with lower IGV values in the three compared sample series. As both, the precipitation of quartz cements and compaction, are a function of the burial history, i.e. effective stresses and experienced temperatures, understanding the interaction of both these processes may enable the prediction of reservoir properties in undrilled areas

Differential diagnosis in spinal and bulbar muscular atrophy clinical and molecular aspects

Kennedy disease is caused by an enlarged trinucleotide repeat sequence within the androgen receptor gene. We report here seven male patients with a benign motor neuron syndrome highly analogous to Kennedy disease but with a normal trinucleotide repeat