Asymptotic behavior of the generalized Becker-D\"oring equations for general initial data

We prove the following asymptotic behavior for solutions to the generalized Becker-D\"oring system for general initial data: under a detailed balance assumption and in situations where density is conserved in time, there is a critical density $\rho_s$ such that solutions with an initial density $\rho_0 \leq \rho_s$ converge strongly to the equilibrium with density $\rho_0$, and solutions with initial density $\rho_0 > \rho_s$ converge (in a weak sense) to the equilibrium with density $\rho_s$. This extends the previous knowledge that this behavior happens under more restrictive conditions on the initial data. The main tool is a new estimate on the tail of solutions with density below the critical density

Adjoint string breaking in 4d SU(2) Yang-Mills theory

We compute the static potential of adjoint sources in SU(2) Yang-Mills theory in four dimensions by numerical Monte Carlo simulations. Following a recent calculation in 2+1 dimensions, we employ a variational approach involving string and gluelump operators and obtain clear evidence for string breaking and the saturation of the potential at large distances. For the string breaking scale we find $r_b \approx 1.25{\rm fm}, 2.3 r_0$, or in units of the lightest glueball, $r_b m_{0++} \approx 9.7$. We furthermore resolve the first excitation of the flux-tube and observe its breaking as well. The result for $r_b$ is in remarkable quantitative agreement with the three-dimensional one.Comment: 15 pages, 3 figures; increased statistics; gauge-fixing clarified; typos correcte

The phase diagram of N_f=3 QCD for small baryon densities

We demonstrate how to locate the critical endpoint of the QCD phase transition by means of simulations at imaginary \mu. For the three flavor theory, we present numerical results for the pseudo-critical line as a function of chemical potential and bare quark mass, as well as the bare quark mass dependence of the endpoint.Comment: 3 pages, 5 eps-figs, Lattice2003(nonzero

QCD phase diagram at small densities from simulations with imaginary mu

We review our results for the QCD phase diagram at baryonic chemical potential mu_B \leq pi T. Our simulations are performed with an imaginary chemical potential mu_I for which the fermion determinant is positive. For 2 flavors of staggered quarks, we map out the phase diagram and identify the pseudo-critical temperature T_c(mu_I). For mu_I/T \leq pi/3, this is an analytic function, whose Taylor expansion is found to converge rapidly, with truncation errors far smaller than statistical ones. The truncated series may then be continued to real mu, yielding the corresponding phase diagram for mu_B \lsim 500 MeV. This approach provides control over systematics and avoids reweighting. We outline our strategy to find the (2+1)-flavor critical point.Comment: 5 pages, 4 figures. To appear in the proceedings of Strong and Electroweak Matter (SEWM 2002), Heidelberg, Germany, 2-5 Oct 200

The QCD Phase Diagram for Three Degenerate Flavors and Small Baryon Density

We present results for the phase diagram of three flavor QCD for \mu_B ~ 500 MeV. Our simulations are performed with imaginary chemical potential \mu_I for which the fermion determinant is positive. Physical observables are then fitted by truncated Taylor series and continued to real chemical potential. We map out the location of the critical line T_c(\mu_B) with an accuracy up to terms of order (\mu_B/T)^6. We also give first results on a determination of the critical endpoint of the transition and its quark mass dependence. Our results for the endpoint differ significantly from those obtained by other methods, and we discuss possible reasons for this.Comment: 20 pages, 10 figures. Eqn (20) corrected, increased statistics, more accurate results. Version to appear in Nucl.Phys.

From energy-density functionals to mean field potentials: a systematic derivation

In this paper we present a systematic method to solve the variational problem of the derivation of a self-consistent Kohn-Sham field from an arbitrary local energy functional. We illustrate this formalism with an application in nuclear physics and give the general mean field associated to the widely used Skyrme effective interaction

Ising analogue to compact-star matter

By constructing an Ising analogue of compact-star matter at sub-saturation density we explored the effect of Coulomb frustration on the nuclear liquid-gas phase transition. Our conclusions is twofold. First, the range of temperatures where inhomogeneous phases form expands with increasing Coulomb-field strength. Second, within the approximation of uniform electron distribution, the limiting point upon which the phase-coexistence region ends does not exhibit any critical behaviour. Possible astrophysics consequences and thermodynamical connections are discussed.Comment: 4 pages, 3 figure

The charge asymmetry from Pomeron-Odderon interference in hard diffractive pi+pi- -electroproduction

The interference of Pomeron and Odderon amplitudes gives rise to a charge asymmetry in the diffractive electroproduction of a pi+pi- -pair. We calculate this charge asymmetry in perturbative QCD in the Born approximation and on the leading Q^2-level. The numerical evaluation shows a sizeable asymmetry in an experimentally accessible kinematical region. We find a characteristic m_{pi+pi} -dependence mainly dictated by the relevant Breit-Wigner-amplitudes and the corresponding phase-shifts.Comment: 4 pages, 3 .eps-figures; Talk given by Ph.H. at the QCD-N'02 workshop in Ferrara; Typos corrected, one reference adde

Human activity modeling and Barabasi's queueing systems

It has been shown by A.-L. Barabasi that the priority based scheduling rules in single stage queuing systems (QS) generates fat tail behavior for the tasks waiting time distributions (WTD). Such fat tails are due to the waiting times of very low priority tasks which stay unserved almost forever as the task priority indices (PI) are "frozen in time" (i.e. a task priority is assigned once for all to each incoming task). Relaxing the "frozen in time" assumption, this paper studies the new dynamic behavior expected when the priority of each incoming tasks is time-dependent (i.e. "aging mechanisms" are allowed). For two class of models, namely 1) a population type model with an age structure and 2) a QS with deadlines assigned to the incoming tasks which is operated under the "earliest-deadline-first" policy, we are able to analytically extract some relevant characteristics of the the tasks waiting time distribution. As the aging mechanism ultimately assign high priority to any long waiting tasks, fat tails in the WTD cannot find their origin in the scheduling rule alone thus showing a fundamental difference between the present and the A.-L. Barabasi's class of models.Comment: 16 pages, 2 figure

Military and political cooperation between Germany and Lithuania in the late 2010s to early 2020s

Since the mid-2010s, Germany has significantly adjusted its approaches to the use of the Bundeswehr, pivoting its strategic focus from regions distant from the Euro-Atlantic community to those within or near it. This has underscored the pressing need to address issues related to securing steadfast allies in Eastern Europe and enhancing cooperation with them. This article aims to explore the current evolution of German-Lithuanian re­lations in both political and military domains. The approach of Germany to the factor of historical memory is demonstrated, along with its aspiration to position itself as the defender of Lithuanian national sovereignty. Yet, there was a notable lack of strategic focus from Germany towards Lithuania in the early 21st century, contributing to a decline in bilateral relations in 2014 and 2015. Amid the confrontation between the 'Western democracies' and Russia, Germany adopted a strategy of gradually but steadily increasing pressure on the opponent. The perception of this approach by Lithuanian elites has shifted from negative in the mid-2010s to increasingly positive as Germany has become more involved in deterrence of Russia. This article explores the process of the Bundeswehr troops' deployment and buildup up to having constituted the 'core' of a multinational brigade in Lithuania under NATO's mandate. The study focuses on the im­pact of military cooperation on political collaborations, as illustrated by the case of the B3 + 1 format, which has brought together high-ranking public officials from the three Baltic states and Germany since 2018. It is concluded that Germany has developed a dependence on Lithuania, driven by the increased desire of the former state to maintain the latter as a reliable junior partner