Newtonian versus relativistic cosmology

We show how the relativistic matter and velocity power spectra behave in different gauges. We construct a new gauge where both spectra coincide with Newtonian theory on all scales. However, in this gauge there are geometric quantities present which do not exist in Newtonian theory, for example the local variation of the Hubble parameter. Comparing this quantity to second order Newtonian quantities, we find that Newtonian theory is inaccurate on scales larger than 10 Mpc. This stresses the importance of relativistic corrections to Newtonian cosmological N-body simulations on these scales.Comment: 10 pages, 3 figures, accepted for publication in Physical Review D (Sept. 2012

Nonseparability of Shared Intentionality

According to recent studies in developmental psychology and neuroscience, symbolic language is essentially intersubjective. Empathetically relating to others renders possible the acquisition of linguistic constructs. Intersubjectivity develops in early ontogenetic life when interactions between mother and infant mutually shape their relatedness. Empirical findings suggest that the shared attention and intention involved in those interactions is sustained as it becomes internalized and embodied. Symbolic language is derivative and emerges from shared intentionality. In this paper, we present a formalization of shared intentionality based upon a quantum approach. From a phenomenological viewpoint, we investigate the nonseparable, dynamic and sustainable nature of social cognition and evaluate the appropriateness of quantum interaction for modelling intersubjectivity

Lösungsbeispiel "pur" oder "angereichert"? Bedingungen und Effekte erfolgreichen Lernens mit einem komplexen Lösungsbeispiel im Bereich empirischer Forschungsmethoden und Statistik.

Starting from problems of knowledge application in the domain of empirical re-search methods and findings from a field study on example-based learning in this domain, a complex worked-out example was employed under experimental conditions. The completeness of the information provided in the example (no gaps vs. gaps) and the provision of questions of understanding (no questions vs. questions) was varied, that is a 2×2-factorial design was used. For all conditions, a distinct learning progress could be achieved by employing the complex worked-out example. However, learning outcomes were neither fostered by the gaps nor by the questions of understanding. The instructional means also had no influence on cognitive load and on motivational aspects. However, various characteristics of the students proved to be important influencing factorsAusgehend von Problemen der Wissensanwendung im Bereich empirischer Forschungsmethoden und den Befunden einer Feldstudie zum beispielbasierten Lernen in diesem Gebiet wurde ein komplexes Lösungsbeispiel unter experimentellen Bedingungen eingesetzt. Variiert wurden die Vollständigkeit der bereit gestellten Beispielinformation (keine Lücken vs. Lücken) und die Vorgabe von Verständnisfragen (keine Fragen vs. Fragen), d.h. es lag ein 2×2-faktorielles Design vor. Über alle Bedingungen hinweg konnte durch Einsatz des komplexen Lösungsbeispiels ein deutlicher Lernfortschritt erzielt werden. Lücken und Verständnisfragen hatten jedoch keinen Einfluss auf den Lernerfolg. Auf die kognitive Belastung und auf motivationale Aspekte wirkten sich beide Maßnahmen ebenfalls nicht aus. Verschiedene Merkmale der Studierenden erwiesen sich jedoch als wichtige Einflussgröße

Pionic Content of Rho-N-N and Rho-N-Delta Vertex Functions

The dynamical content of rho-N-N and rho-N-Delta vertex functions is studied with a mesonic model. A set of coupled integral equations satisfied by these vertex functions were solved self-consistently. These soulutions indicate that the dominant mesonic content arises from di-pion dynamics. With the experimentally determined pion-baryon-baryon coupling constants and ranges as input, the model predicts a g_{\rho NN} that agrees with the meson-exchange-potential results. On the other hand, it predicts a smaller f_{\rho N\Delta} and much softer form factors. Implications of the findings on the use of phenomenological coupling constants in nuclear reaction studies are discussed.Comment: 9 pages, 2 figures will be furnished upon request; LA-UR-94-126

Constraints on the Optical Depth of Galaxy Groups and Clusters

Future data from galaxy redshift surveys, combined with high-resolutions maps of the cosmic microwave background, will enable measurements of the pairwise kinematic Sunyaev–Zel'dovich (kSZ) signal with unprecedented statistical significance. This signal probes the matter-velocity correlation function, scaled by the average optical depth (τ) of the galaxy groups and clusters in the sample, and is thus of fundamental importance for cosmology. However, in order to translate pairwise kSZ measurements into cosmological constraints, external constraints on τ are necessary. In this work, we present a new model for the intracluster medium, which takes into account star formation, feedback, non-thermal pressure, and gas cooling. Our semi-analytic model is computationally efficient and can reproduce results of recent hydrodynamical simulations of galaxy cluster formation. We calibrate the free parameters in the model using recent X-ray measurements of gas density profiles of clusters, and gas masses of groups and clusters. Our observationally calibrated model predicts the average τ₅₀₀ (i.e., the integrated τ within a disk of size R ₅₀₀) to better than 6% modeling uncertainty (at 95% confidence level). If the remaining uncertainties associated with other astrophysical uncertainties and X-ray selection effects can be better understood, our model for the optical depth should break the degeneracy between optical depth and cluster velocity in the analysis of future pairwise kSZ measurements and improve cosmological constraints with the combination of upcoming galaxy and CMB surveys, including the nature of dark energy, modified gravity, and neutrino mass.National Science Foundation (U.S.) (AST-1412768)United States. National Aeronautics and Space Administration (GO4-15122A)United States. National Aeronautics and Space Administration (contract GO5-16141X

Interview with Reinhard Flender, director of the Peermusic Classical

Peermusic Classical is the European classical music branch of the Peermusic group that was founded in 1928 and that is today the largest music editor worldwide with 600,000 works in its catalogue. ResMusica met with its director Reinhard Flender regarding The Passenger by Weinberg.Peermusic Classical est la branche musique classique européenne du groupe Peermusic fondé en 1928 et aujourd’hui le plus grand éditeur mondial de musique avec 600 000 œuvres à son catalogue. ResMusica a rencontré son directeur Reinhard Flender, parlant un français parfait, à propos de La Passagère de Weinberg.Peermusic Classical is de Europese klassieke muziektak van de Peermusicgroep, gesticht in 1928 en vandaag de grootste muziekuitgever ter wereld met een catalogus van 600 000 werken. ResMusica ontmoette directeur Reinhard Flender, die ons in perfect Frans inwijdde in Weinbergs The Passenger

Entretien avec Reinhard Flender, directeur de Peermusic Classical

Peermusic Classical est la branche musique classique européenne du groupe Peermusic fondé en 1928 et aujourd’hui le plus grand éditeur mondial de musique avec 600 000 œuvres à son catalogue. ResMusica a rencontré son directeur Reinhard Flender, parlant un français parfait, à propos de La Passagère de Weinberg.Peermusic Classical is the European classical music branch of the Peermusic group that was founded in 1928 and that is today the largest music editor worldwide with 600,000 works in its catalogue. ResMusica met with its director Reinhard Flender regarding The Passenger by Weinberg.Peermusic Classical is de Europese klassieke muziektak van de Peermusicgroep, gesticht in 1928 en vandaag de grootste muziekuitgever ter wereld met een catalogus van 600 000 werken. ResMusica ontmoette directeur Reinhard Flender, die ons in perfect Frans inwijdde in Weinbergs The Passenger