Exchange operator formalism for N-body spin models with near-neighbors interactions

We present a detailed analysis of the spin models with near-neighbors interactions constructed in our previous paper [Phys. Lett. B 605 (2005) 214] by a suitable generalization of the exchange operator formalism. We provide a complete description of a certain flag of finite-dimensional spaces of spin functions preserved by the Hamiltonian of each model. By explicitly diagonalizing the Hamiltonian in the latter spaces, we compute several infinite families of eigenfunctions of the above models in closed form in terms of generalized Laguerre and Jacobi polynomials.Comment: RevTeX, 31 pages, no figures; important additional conten

Forward Analysis and Model Checking for Trace Bounded WSTS

We investigate a subclass of well-structured transition systems (WSTS), the bounded---in the sense of Ginsburg and Spanier (Trans. AMS 1964)---complete deterministic ones, which we claim provide an adequate basis for the study of forward analyses as developed by Finkel and Goubault-Larrecq (Logic. Meth. Comput. Sci. 2012). Indeed, we prove that, unlike other conditions considered previously for the termination of forward analysis, boundedness is decidable. Boundedness turns out to be a valuable restriction for WSTS verification, as we show that it further allows to decide all $\omega$-regular properties on the set of infinite traces of the system

Quasi-exactly Solvable Lie Superalgebras of Differential Operators

In this paper, we study Lie superalgebras of $2\times 2$ matrix-valued first-order differential operators on the complex line. We first completely classify all such superalgebras of finite dimension. Among the finite-dimensional superalgebras whose odd subspace is nontrivial, we find those admitting a finite-dimensional invariant module of smooth vector-valued functions, and classify all the resulting finite-dimensional modules. The latter Lie superalgebras and their modules are the building blocks in the construction of QES quantum mechanical models for spin 1/2 particles in one dimension.Comment: LaTeX2e using the amstex and amssymb packages, 24 page

Can online civic education induce democratic citizenship? Experimental evidence from a new democracy

How can democratic values and behavior be induced in new democracies? We designed and tested three original civic education interventions to answer this question, using Tunisia as a case study. Participants were recruited through Facebook and Instagram where they were randomly assigned to either one of three treatment groups or a placebo. Two treatments were derived from prospect theory, emphasizing the gains of a democratic system, or the losses of an autocratic system. A third treatment, derived from self-efficacy theory, provided practical information regarding participation in the upcoming 2019 elections. Our findings suggest that online civic education has a considerable effect on democratic citizenship, including a significant reduction in authoritarian nostalgia and increasing intended political behavior. We further find differences between the three treatments, with the loss and gain treatments having overall more consistent impact than self-efficacy, though the latter frame has notable effects on political efficacy and registration

On the construction of evolution equations admitting a master symmetry

A method for constructing evolution equations admitting a master symmetry is proposed. Several examples illustrating the method are presented. It is also noted that for certain evolution equations master symmetries can be useful for obtaining new conservation laws from a given one

Personenmarken erfolgreich managen : ein markenpersönlichkeitsbasierter Steuerungsansatz

Personen, wie beispielsweise Sportler, Politiker, Künstler oder Manager, die ihre Leistungen und zunehmend auch sich selb st vermarkten, können als Marken verstanden werden. Ähnlich wie Gütermarken stehen auch Personenmarken immer häufiger vor der Herausforderung, durch eine erfolgreiche Differenzierung im Verdrängungswettbewerb zu bestehen. Trotz ihres enormen wirtschaftlichen Potenzials existiert für Personenmarken bislang kein systematischer Ansatz zur Differenzierung gegenüber der Konkurrenz und somit auch keine Grundlage für ihre effektive Vermarktung. Im vorliegenden Beitrag wird daher zunächst dargestellt, dass das Konzept der Marke auf Personen übertragen und der im Gütermarketing erfolgreich eingesetzte Differenzierungsansatz der Markenpersönlichkeit auch im Kontext von Personenmarken angewendet werden kann. In einem weiteren Schritt werden die im Rahmen einer empirischen Studie ermittelten Einflussfaktoren der Markenpersönlichkeit von Personenmarken vorgestellt und ihre Einsatzmöglichkeiten für ein effektives strategisches Management von Personenmarken beschrieben

The Isomorphism Relation Between Tree-Automatic Structures

An $\omega$-tree-automatic structure is a relational structure whose domain and relations are accepted by Muller or Rabin tree automata. We investigate in this paper the isomorphism problem for $\omega$-tree-automatic structures. We prove first that the isomorphism relation for $\omega$-tree-automatic boolean algebras (respectively, partial orders, rings, commutative rings, non commutative rings, non commutative groups, nilpotent groups of class n >1) is not determined by the axiomatic system ZFC. Then we prove that the isomorphism problem for $\omega$-tree-automatic boolean algebras (respectively, partial orders, rings, commutative rings, non commutative rings, non commutative groups, nilpotent groups of class n >1) is neither a $\Sigma_2^1$-set nor a $\Pi_2^1$-set