On Quantum Groups in the Hubbard Model with Phonons

The correct Hamiltonian for an extended Hubbard model with quantum group symmetry as introduced by A. Montorsi and M. Rasetti is derived for a D-dimensional lattice. It is shown that the superconducting SUq(2) holds as a true quantum symmetry only for D = 1 and that terms of higher order in the fermionic operators in addition to phonons are required for a quantum symmetric hamiltonian. The condition for quantum symmetry is "half filling" and there is no local electron-phonon coupling. A discussion of Quantum symmetries in general is given in a formalism that should be readily accessible to non Hopf-algebraists.Comment: latex, 17 page

Developing SOEPsurvey and SOEPservice: The (Near) Future of the German Socio-Economic Panel Study (SOEP)

Das Sozio-oekonomische Panel (SOEP) ist als multidisziplinäres Haushaltspanel, das Informationen zu allen Personen, die in einem Panel-Haushalt leben, erhebt und damit alle Altersjahrgänge abdeckt, nach 25 Jahren Laufzeit auch zu einer Kohorten- Studie geworden. Der zunehmende Erfolg der Forschungsinfrastruktur-Einrichtung SOEP speist sich in erster Linie daraus, dass die Analysekraft von Längsschnittstudien mit jedem weiteren Erhebungsjahr zunimmt. Hinzu kommen im Falle des SOEP seit Beginn an eine lange Reihe von Innovationen bei der Erhebung, Datenaufbereitung und Nutzer-Service. Deswegen gilt es zu überlegen, wie die wissenschaftliche Power des SOEP weiter gestärkt werden kann. Nicht zuletzt auch, da es für neue, spezialisierte Panel-Studien (wie das Nationale Bildungspanel oder das DFG-geförderte Familienpanel PAIRFAM) eine Referenz und ggf. Verankerung der Hochrechnung darstellt. Zudem kann das SOEP künftig eine größere Rolle als ,,Kontroll-Stichprobe" für Interventions-Studien spielen; etwa im Bereich der Kindheitsentwicklung. Auf diese neuen Rollen muss es vorbereitet sein. Die im SOEP in den letzten Jahren realisierten Erhebungsinnovationen wie z. B. die Inkorporation psychologischer Konzepte, physische Gesundheitsmessungen (Greifkraft), die Messung kognitiver Fähigkeiten und die Erprobung von Verhaltens- Experimenten werden in anderen Panel-Studien aufgegriffen und auf eine größere Stichprobenbasis gestellt. Im UK wird mit ,,Understanding Society" ein Haushaltspanel mit 40.000 Haushalten begonnen; in den Niederlanden wird mit MESS ein Haushaltspanel von über 5.000 Haushalten für innovative Messmethoden zur Verfügung gestellt. Die Erhebungsinhalte des SOEP werden von den Forschungs- und Politikberatungs-Communities unverändert stark nachgefragt. In UK hat ein für ,,Understanding Society" breit angelegter Konsultationsprozess keine grundsätzlich neuen Befragungsinhalte zu Tage gefördert, die das SOEP nicht bereits enthält oder die für das SOEP ohnehin im Gespräch sind. Wichtiger als die ,,Entdeckung" völlig neuer Erhebungsinhalte ist das thematische wie zeitliche ,,Zuschneiden" der Details von Befragungsinhalten auf (zugespitzte) neue (theoretische) Fragestellungen und dabei gleichzeitig bewährte sowie viel genutzte zentrale Befragungsinhalte und deren Befragungsrhythmen beizubehalten. Das ,,Maßschneidern" von Erhebungsinhalten wird in den nächsten Jahren die eigentliche Herausforderung für Infrastruktur- Erhebungen wie die PSID, ,,Understanding Society" und das SOEP sein. Bei den Erhebungsinhalten sollten die ,,Ränder" des Lebenslaufs eine größere Rolle spielen, da diese von Haushalts-Panels besonders gut erfasst werden können. Diese Verbesserungen der Erhebungen beziehen sich einerseits auf die fötale Phase von in das SOEP hineingeborenen Kindern und die (frühe) Kindheit, andererseits auf die letzte Lebensphase und das Sterben. In der Mitte des Lebenslaufs werden verbesserte Fragen zum Einkommen, Sparen und Vermögen sowie auch psychologische Konstrukte eine zentrale Rolle spielen, außerdem gezielte Fragen (event triggered questionnaires) in Verbindung mit zentralen Lebensereignissen wie z. B. Eheschließung, Scheidung, Eintritt in und Austritt aus Arbeitslosigkeit. Es wird die Etablierung einer SOEP-"Innovations-Stichprobe" vorbereitet, um theoriegeleitete Forschungsfragen gezielter unterstützen zu können. Dazu wird es auch notwendig sein, neue Messkonzepte zu erproben (z. B. die Erhebung von Biomarkern, qualitative Erhebungen, aber auch Experimente und gezielte Interventionsstudien). Um die Power von Längsschnittdaten von Anfang an für die Innovations-Stichprobe ausnutzen zu können, ist geplant, zwei kleinere Teilstichproben des SOEP, die seit 1998 bzw. 2006 laufen (Subsamples E und H), in die Innovationsstichprobe zu überführen. Um die statistische Power langlaufender Längsschnittdaten entscheidend zu verbessern, schätzen wir eine Mindestfallzahl von etwa 500 Personen pro Geburtsund Alterskohorte für ausreichend ein. Um dieses Ziel zu erreichen, muss die Fallzahl des SOEP-Standard-Samples erhöht werden. Als ,,Nebeneffekt" werden dadurch wesentlich bessere Analysen für relativ kleine Gruppen in der Bevölkerung möglich; etwa für allein Erziehende oder bestimme Immigrantengruppen. Außerdem verbessern sich als weiterer ,,Nebeneffekt" auch regionale Analysemöglichkeiten, z. B. für die meisten Bundesländer und in großen Bundesländern bis hin zu Regierungsbezirken (oder ähnlich abgegrenzten regionalen Einheiten). In letzter Zeit wird immer deutlicher, welche große Bedeutung das SOEP als ,,Referenz-Datensatz" für spezialisierte und vom SOEP völlig unabhängige Erhebungen hat (neben Beobachtungsstudien, wie etwa Zwillings-Studien, auch Labor- und Interventions-Studien). Zur Unterstützung dieser Funktion ist eine neue Art von Service, der in Deutschland bislang nicht vorgehalten wird, notwendig (Beratung von Spezial-Erhebungen; ggf. Datenaufbereitung von längsschnittlichen Spezial-Erhebungen), der auch in ein Datenservicezentrum eingebracht werden könnte. After 25 years as a multidisciplinary household panel containing information on all individuals residing in panel households and thus covering all age cohorts, the German Socio-Economic Panel (SOEP) has become a true cohort study as well. The increasing success of the SOEP research infrastructure comes above all from the increasing analytical power that longitudinal studies attain with each successive survey year. In the case of SOEP, a long series of innovations in surveying, data preparation, and user service have also played a major role. For this reason, it is important to consider how the scientific capacity of SOEP can be further enhanced-- not least of all since the SOEP can form a key point of reference (or "anchor") for new, specialized panel studies (such as the National Educational Panel and the family panel PAIRFAM, funded by the German Research Foundation). Furthermore SOEP can become a kind of "control sample" for intervention studies, for example, in the field of child development. The SOEP survey and its governance structures must be prepared for these new tasks. The numerous innovations introduced into SOEP in recent years--questions dealing with psychological concepts, physical health measures (grip strength), measures of cognitive capabilities, and behavioral experiments--have been incorporated into other panel studies as well, and thus provided with a larger sample base. In the UK, the "Understanding Society" household panel study was launched with 40,000 households; in the Netherlands, the MESS household panel study of over 5,000 households offered a new basis for testing innovative measurement methods. The results of the SOEP survey are in continuing high demand in the research and policy advisory community. From our point of view, the large-scale consultation process conducted to define the content of the UK survey "Understanding Society" failed to identify any fundamentally new survey content that the SOEP either did not already contain or that was not already being discussed for the SOEP. More important than "discovering" entirely new survey areas is "tailoring" the details of existing survey content to address new, more specific (theoretical) questions, and thus maintaining proven and widely used elements of survey content. The "tailoring" of survey content will be the real challenge facing infrastructure surveys like PSID, "Understanding Society," and the SOEP in the coming years. In the future, the "margins" of the life course should play a stronger role in survey content, since household panels are able to provide outstanding data of these life phases. The SOEP, and other household panel surveys, can be improved, on the one hand, by including the fetal phase of life and early childhood for children born into the panel, and on the other, by including late life and death. In the middle of the life course, improved questions on income, savings, and wealth as well as psychological constructs will play a central role, as will specific questions (in "eventtriggered" questionnaires) on central life occurrences such as marriage, divorce, and entry into and exit from unemployment. Current plans for SOEP foresee the addition of an "Innovation Sample" that will make it possible to better address theory-based research questions required for testing new measurement concepts (e.g., the surveying of biomarkers, qualitative surveys, but also experiments and targeted intervention studies). In order to exploit the power of longitudinal data from the outset, we plan to incorporate two smaller SOEP subsamples that have been running since 1998 and 2006 (Subsamples E and H, respectively) into the Innovation Sample. In order to decisively improve the statistical power of long-term longitudinal data, we believe that a minimum case number of about 500 persons per birth and age cohort is required. In order to reach this goal, the case number in the SOEP standard samples needs to be increased. A positive side-effect of this enlargement would be a significantly improved potential for analyses of relatively small groups within the population: for example, lone parents or specific immigrant groups. Another positive side-effect would be an improved potential for regional analyses: for example, for the majority of federal states. In recent times, the importance of SOEP as a "reference dataset" for specialized surveys which are independent from SOEP (observational studies such as twin studies, and laboratory and intervention studies) has become strikingly evident. To enhance this important function, new types of service are needed (advice on special surveys, possibly also data preparation for special surveys), which could become part of a Data Service Center.Household Panels, German Socio-Economic Panel Study, SOEP

Voros product and the Pauli principle at low energies

Using the Voros star product, we investigate the status of the two particle correlation function to study the possible extent to which the previously proposed violation of the Pauli principle may impact at low energies. The results show interesting features which are not present in the computations made using the Moyal star product.Comment: 5 pages LateX, minor correction

Explicit attention interferes with selective emotion processing in human extrastriate cortex

BACKGROUND: Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN) for pleasant and unpleasant compared to neutral images (~150–300 ms poststimulus). The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. RESULTS: Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b). Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. CONCLUSION: The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task-relevant stimuli. The present data suggest that interference of emotion processing by competing task demands is a more general phenomenon extending to the domain of feature-based attention. Furthermore, the results are inconsistent with the notion of effortlessness, i.e., early emotion discrimination despite concurrent task demands. These findings implicate to assess the presumed automatic nature of emotion processing at the level of specific aspects rather than considering automaticity as an all-or-none phenomenon

Aharonov-Casher effect for spin one particles in a noncommutative space

In this work the Aharonov-Casher (AC) phase is calculated for spin one particles in a noncommutative space. The AC phase has previously been calculated from the Dirac equation in a noncommutative space using a gauge-like technique [17]. In the spin-one, we use kemmer equation to calculate the phase in a similar manner. It is shown that the holonomy receives non-trivial kinematical corrections. By comparing the new result with the already known spin 1/2 case, one may conjecture a generalized formula for the corrections to holonomy for higher spins.Comment: 9 page

Fruit crops 1990: a summary of research

Orchard temperature profiles in spring frost conditions / R. D. Brazee, R. D. Fox and D. C. Ferree -- Orchard sprayers: how much spray moves out of the orchard? / R. D. Fox, D. L. Reichard, R. D. Brazee, and F. R. Hall -- Influence of pruning treatments on mature spur-bound 'Starkrimson Delicious' apple trees / D. C. Ferree, J. C. Schmid, J. R. Schupp and I. J. Warrington -- The winter of 1983-84: a test winter for Ohio's fruit crops / C. K. Chandler and D. C. Ferree -- Performance of apple roostock, cultivars and cultural treatments under the stress of the 1988 drought / D. C. Ferree and J. C. Schmid -- Performance of a spur and standard Delicious strain in a slender spindle system / D. C. Ferree and J. C. Schmid -- Survey of Ohio strawberry growers: present practice and future directions / J. C. Scheerens and G. L. Brenneman -- Orchard crop loss assessments: a precondition for improved crop protection decisions / F. R. Hall -- Evaluation of compounds for control of foliar grape phylloxera, Daktulosphaira vitifoliae (Fitch) in Ohio / M. J. McLeod and R. N. Williams -- Marketing Ohio Strawberries / W. T. Rhodus and R. C. Fun

EUV spectroscopy of Sn5+-Sn(10+)ions in an electron beam ion trap and laser-produced plasmas

Emission spectra from multiply-charged Sn5+ –Sn10+ions are recorded from an electron beam ion trap (EBIT) and from laser-produced plasma (LPP) in the extreme ultraviolet range relevant for nanolithographic applications. Features in the wavelength regime between 12.6 and 20.8 nm are studied. Using the Cowan code, emission line features of the charge-state-resolved Sn ion spectra obtained from the EBIT are identified. Emission features from tin LPP either from a liquid micro-droplet or planar solid target are subsequently identified and assigned to specific charge states using the EBIT data. For the planar solid tin target, the 4d–5p transitions of Sn8+ –Sn10+ions are shown to dominate the long-wavelength part of the measured spectrum and transitions of type 4d–4f + 4p–4d are visible in absorption. For the droplet target case, a clear increase in the charge state distribution with increasing laser intensity is observed. This qualitatively demonstrates the potential of using long-wavelength out-of-band emission features to probe the charge states contributing to the strong unresolved transition array at 13.5 nm relevant for nanolithography

Noncommutative Solitons of Gravity

We investigate a three-dimensional gravitational theory on a noncommutative space which has a cosmological constant term only. We found various kinds of nontrivial solutions, by applying a similar technique which was used to seek noncommutative solitons in noncommutative scalar field theories. Some of those solutions correspond to bubbles of spacetimes, or represent dimensional reduction. The solution which interpolates $G_{\mu\nu}=0$ and Minkowski metric is also found. All solutions we obtained are non-perturbative in the noncommutative parameter $\theta$, therefore they are different from solutions found in other contexts of noncommutative theory of gravity and would have a close relation to quantum gravity.Comment: 29 pages, 5 figures. v2: minor corrections done in Section 3.1 and Appendix, references added. v3, v4: typos correcte

Bicovariant Differential Geometry of the Quantum Group SLh(2)SL_h(2)

There are only two quantum group structures on the space of two by two unimodular matrices, these are the $SL_q(2)$ and the $SL_h(2)$ [9-13] quantum groups. One can not construct a differential geometry on $SL_q(2)$, which at the same time is bicovariant, has three generators, and satisfies the Liebnitz rule. We show that such a differential geometry exists for the quantum group $SL_h(2)$ and derive all of its properties