The chemical potential for the inhomogeneous electron liquid in terms of its kinetic and potential parts with special consideration of the surface pote ntial step and BCS-BEC crossover

The chemical potential $\mu$ of a many-body system is valuable since it carries fingerprints of phase changes. Here, we summarize results for $\mu$ for a thre e-dimensional electron liquid in terms of average kinetic and potential energie s per particle. The difference between $\mu$ and the energy per particle is fou nd to be exactly the electrostatic potential step at the surface. We also prese nt calculations for an integrable one-dimensional many-body system with delta f unction interactions, exhibiting a BCS-BEC crossover. It is shown that in the B CS regime the chemical potential can be expressed solely in terms of the ground -state energy per particle. A brief discussion is also included of the strong c oupling BEC limit.Comment: 4 pages 3 figure

Symmetry breaking and singularity structure in Bose-Einstein condensates

We determine the trajectories of vortex singularities that arise after a single vortex is broken by a discretely symmetric impulse in the context of Bose-Einstein condensates in a harmonic trap. The dynamics of these singularities are analyzed to determine the form of the imprinted motion. We find that the symmetry-breaking process introduces two effective forces: a repulsive harmonic force that causes the daughter trajectories to be ejected from the parent singularity, and a Magnus force that introduces a torque about the axis of symmetry. For the analytical non-interacting case we find that the parent singularity is reconstructed from the daughter singularities after one period of the trapping frequency. The interactions between singularities in the weakly interacting system do not allow the parent vortex to be reconstructed. Analytic trajectories were compared to the actual minima of the wavefunction, showing less 0.5% error for impulse strength of (v=0.00005). We show that these solutions are valid within the impulse regime for various impulse strengths using numerical integration of the Gross-Pitaevskii equation. We also show that the actual duration of the symmetry breaking potential does not significantly change the dynamics of the system as long as the strength is below (v=0.0005).Comment: 14 pages, 10 figure

Mutual information between geomagnetic indices and the solar wind as seen by WIND : implications for propagation time estimates

The determination of delay times of solar wind conditions at the sunward libration point to effects on Earth is investigated using mutual information. This measures the amount of information shared between two timeseries. We consider the mutual information content of solar wind observations, from WIND, and the geomagnetic indices. The success of five commonly used schemes for estimating interplanetary propagation times is examined. Propagation assuming a fixed plane normal at 45 degrees to the GSE x-axis (i.e. the Parker Spiral estimate) is found to give optimal mutual information. The mutual information depends on the point in space chosen as the target for the propagation estimate, and we find that it is maximized by choosing a point in the nightside rather than dayside magnetosphere. In addition, we employ recurrence plot analysis to visualize contributions to the mutual information, this suggests that it appears on timescales of hours rather than minutes

The Bulk RS KK-gluon at the LHC

We study the possibility of discovering and measuring the properties of the lightest Kaluza-Klein excitation of the gluon in a Randall-Sundrum scenario where the Standard Model matter and gauge fields propagate in the bulk. The KK-gluon decays primarily into top quarks. We discuss how to use the $t \bar{t}$ final states to discover and probe the properties of the KK-gluon. Identification of highly energetic tops is crucial for this analysis. We show that conventional identification methods relying on well separated decay products will not work for heavy resonances but suggest alternative methods for top identification for energetic tops. We find, conservatively, that resonances with masses less than 5 TeV can be discovered if the algorithm to identify high $p_T$ tops can reject the QCD background by a factor of 10. We also find that for similar or lighter masses the spin can be determined and for lighter masses the chirality of the coupling to $t\bar t$ can be measured. Since the energetic top pair final state is a generic signature for a large class of new physics as the top quark presumably couples most strongly to the electroweak symmetry breaking sector, the methods we have outlined to study the properties of the KK-gluon should also be important in other scenarios.Comment: 21 pages, 13 figure

Statistical Description of Hydrodynamic Processes in Ionic Melts with taking into account Polarization Effects

Statistical description of hydrodynamic processes for ionic melts is proposed with taking into account polarization effects caused by the deformation of external ionic shells. This description is carried out by means of the Zubarev nonequilibrium statistical operator method, appropriate for investigations of both strong and weak nonequilibrium processes. The nonequilibrium statistical operator and the generalized hydrodynamic equations that take into account polarization processes are received for ionic-polarization model of ionic molten salts when the nonequilibrium averaged values of densities of ions number, their momentum, dipole momentum and total energy are chosen for the reduced description parameters. A spectrum of collective excitations is investigated within the viscoelastic approximation for ion-polarization model of ionic melts.Comment: 24 pages, RevTex4.1-format, no figure

Coordinating Intergenerational Redistribution and the Repayment of Public Debt

Is there a link between public debt and wealth inequality? Could government bondholders use intra-generational redistribution strategically to make the repayment of debt politically viable? Using a two-generations game-theoretic model, we identify coordination and divide-and-conquer as key factors. By coordinating their bond investments, the old generation may secure a majority favoring debt repayment. As a consequence, coordination mediates the impact of wealth inequality on public debt. Furthermore, ease of coordination offers another compelling reason why declining population growth fosters the accumulation of public debt. We test our model in a laboratory experiment and confirm the central predictions

Coordinating intergenerational redistribution and the repayment of public debt: an experimental test of Tabellini (1991)

Is there a link between public debt and wealth inequality? Could government bondholders use intra-generational redistribution strategically to make the repayment of debt politically viable? We reconsider the model of Tabellini (J Polit Econ 99:335–357, 1991) and expose the role of coordination and divide-and-conquer. By coordinating their bond investments, the old generation splits up the young generation and secures a majority favoring debt repayment. Coordination therefore mediates the impact of wealth inequality on public debt. We test the model in a laboratory experiment and find that subjects often coordinate to exploit the link between inter- and intragenerational redistribution. Hence, coordination plays an important role in the strategic creation and exploitation of minorities, and thus in the accumulation of public debt

The Population Dynamics of Two Rodents in Two Coastal Marshes in Virginia

The communities of small mammals were evaluated for 13 months with capture-mark-recapture methods in two Spartina-Juncus marshes of the Atlantic coast in Northampton County, Virginia. Small mammals were trapped for three days each month using live traps placed on floats on two study grids. Two rodents were numerically dominant (~90% of small mammals) there: marsh rice rat, Oryzomys palustris, and meadow vole, Microtus pennsylvanicus. Monthly estimates of population density were greater for rice rats (peak: 45/ha) than for those of meadow voles (peak: 30/ha). Survival rates were generally low, especially for rice rats, indicating highly vagile populations. Both species had greatest breeding activity in spring and autumn, with lower rates in summer and winter. Sex ratios favored males in rice rats but were unity in meadow voles. Although marsh rice rats, being semi-aquatic and capable swimmers, are more highly adapted to living in flooded marsh environments, meadow voles can thrive there too