Configuration mixing within the energy density functional formalism: pathologies and cures

Configuration mixing calculations performed in terms of the Skyrme/Gogny Energy Density Functional (EDF) rely on extending the Single-Reference energy functional into non-diagonal EDF kernels. The standard way to do so, based on an analogy with the pure Hamiltonian case and the use of the generalized Wick theorem, is responsible for the recently observed divergences and steps in Multi-Reference calculations. We summarize here the minimal solution to this problem recently proposed [Lacroix et al, arXiv:0809.2041] and applied with success to particle number restoration[Bender et al, arXiv:0809.2045]. Such a regularization method provides suitable corrections of pathologies for EDF depending on integer powers of the density. The specific case of fractional powers of the density[Duguet et al, arXiv:0809.2049] is also discussed.Comment: 5 pages, Proceedings of the French-Japanese Symposium, September 2008. To be published in Int. J. of Mod. Phys.

Pairing correlations beyond the mean field

We discuss dynamical pairing correlations in the context of configuration mixing of projected self-consistent mean-field states, and the origin of a divergence that might appear when such calculations are done using an energy functional in the spirit of a naive generalized density functional theory.Comment: Proceedings of the XIII Nuclear Physics Workshop ``Maria and Pierre Curie'' on ``Pairing and beyond - 50 years of the BCS model'', held at Kazimierz Dolny, Poland, September 27 - October 1, 2006. Int. J. Mod. Phys. E, in prin

Interpretation of satellite images of the Republic of Niger

Interpretations of LANDSAT pictures were carried out for an area located in the west of the Niger Republic in the geological, hydrogeological and pedological sectors. Checking of the extent of vegetation and use of the soils and effects of desertification for the purpose of yearly map making was carried out. The proposed control of land use may be optimized by the direct reception of LANDSAT data by the receiving station planned for Ouagadougou. Since that station will not be operating before 1983, the establishment of a mobile reception station in the Republic of Niger to enable the installation of the required control system is advised

Spatially resolved spectroscopy of Coma cluster early-type galaxies IV. Completing the dataset

The long-slit spectra obtained along the minor axis, offset major axis and diagonal axis are presented for 12 E and S0 galaxies of the Coma cluster drawn from a magnitude-limited sample studied before. The rotation curves, velocity dispersion profiles and the H_3 and H_4 coefficients of the Hermite decomposition of the line of sight velocity distribution are derived. The radial profiles of the Hbeta, Mg, and Fe line strength indices are measured too. In addition, the surface photometry of the central regions of a subsample of 4 galaxies recently obtained with Hubble Space Telescope is presented. The data will be used to construct dynamical models of the galaxies and study their stellar populations.Comment: 40 pages, 7 figures, 6 tables. Accepted for publication in ApJ

Constraints on galaxy formation from alpha-enhancement in luminous elliptical galaxies

We explore the formation of alpha-enhanced and metal-rich stellar populations in the nuclei of luminous ellipticals under the assumption of two extreme galaxy formation scenarios based on hierarchical clustering, namely a fast clumpy collapse and the merger of two spirals. We investigate the parameter space of star formation time-scale, IMF slope, and stellar yields. In particular, the latter add a huge uncertainty in constraining time-scales and IMF slopes. We find that -- for Thielemann, Nomoto & Hashimoto nucleosynthesis -- in a fast clumpy collapse scenario an [alpha/Fe] overabundance of approx. 0.2 dex in the high metallicity stars can be achieved with a Salpeter IMF and star formation time-scales of the order 10^9 yr. The scenario of two merging spirals which are similar to our Galaxy, instead, fails to reproduce alpha-enhanced abundance ratios in the metal-rich stars, unless the IMF is flattened during the burst ignited by the merger. This result is independent of the burst time-scale. We suggest that abundance gradients give hints to distinguish between the two extreme formation scenarios considered in this paper.Comment: Accepted for publication in MNRAS, LaTex 2.09 with mn.sty, 13 pages, 5 figure

Ten Conversations about Identity Preservation: Implications for Cooperatives

Motivation: While it appears the modern economy demands ever increasing amounts of differentiation, opportunities for grain producers to create and capture significant new sources of value remains elusive. Opportunities appear to loom large to help remove risk and improve quality in the grain supply chain through preservation of product identity, producers, producer groups, and cooperatives are frustrated at the low level of value available to them from IP demand. Why do premiums remain low? And, what is the role of group action in these new differentiated markets? Objectives: This research report helps to explain this apparent paradox underlying the economics of the value proposition for IP grains. Methodology: Needs assessments were conducted on procurement executives using a semi-structured instrument. Results: The study demonstrates that understanding identity preservation business opportunities requires an understanding of the buy-side proposition. Respondents described how they balance the risk mitigation and market uplift features of a supply offering with the risks of narrowing the supply base. A model of the buyer's calculus is constructed. The results show how for producers and producer groups to drive value up the chain they need to shift away from solely a new product focus. Instead attention needs to be directed towards technologies, delivery systems, and organizational models that when bundled with new products make end-users more competitive. A second insight was the limited role of group action in meeting end-user needs. Where value markets existed, internalized groups rather than "arm's length" group transactions were the norm. Plan for Discussion: The cooperative movement was grounded in group action giving individual producers power in the market. The motivation to unite was very clear. In the post-industrial agrifood system though, why do buyers want to purchase from a group? What is the role of the group, from a buy-side perspective, in the modern economy? How should effective groups be structured? Key Words: identity preservation, supply chain management, value creation, group actionidentity preservation, supply chain management, value creation, group action, Agribusiness,

Pion Loop Contribution to the Electromagnetic Pion Charge Radius

A phenomenological Dyson-Schwinger equation approach to QCD, formalised in terms of a QCD based model field theory, is used to calculate the electromagnetic charge radius of the pion. The contributions from the quark core and pion loop, as defined in this approach, are identified and compared. It is shown explicitly that the divergence of the charge radius in the chiral limit is due to the pion loop and that, at the physical value of the pion mass, this loop contributes less than 15\% to $\langle r^2_\pi\rangle$; i.e. the quark core is the dominant determining characteristic for the pion. This suggests that quark based models which fail to reproduce the $\ln\,m_\pi$ divergence of $\langle r^2_\pi\rangle$ may nevertheless incorporate the dominant characteristic of the pion: its quark core.Comment: 22 Pages, 5 figures uuencoded and appended to this file, REVTEX 3.0. ANL-PHY-7663-TH-93, UNITUE-THEP-13/199

TOPEX orbit determination using GPS signals plus a sidetone ranging system

The GPS orbit determination was studied to see how well the radial coordinate for altimeter satellites such as TOPEX could be found by on board measurements of GPS signals, including the reconstructed carrier phase. The inclusion on altimeter satellites of an additional high accuracy tracking system is recommended. It is suggested that a sidetone ranging system is used in conjunction with TRANET 2 beacons

Guidance, flight mechanics and trajectory optimization. Volume 12 - Relative motion, guidance equations for terminal rendezvous

Equations of relative motion and guidance for orbital transfer and docking maneuvers in spacecraft rendezvou

The structure of supersymmetry in PT{\cal PT} symmetric quantum mechanics

The structure of supersymmetry is analyzed systematically in ${\cal PT}$ symmetric quantum mechanical theories. We give a detailed description of supersymmetric systems associated with one dimensional ${\cal PT}$ symmetric quantum mechanical theories. We show that there is a richer structure present in these theories compared to the conventional theories associated with Hermitian Hamiltonians. We bring out various properties associated with these supersymmetric systems and generalize such quantum mechanical theories to higher dimensions as well as to the case of one dimensional shape invariant potentials.Comment: 15 pages, some explanations included, references adde