Confinement in the q-state Potts model: an RG-TCSA study

In the ferromagnetic phase of the q-state Potts model, switching on an external magnetic field induces confinement of the domain wall excitations. For the Ising model (q = 2) the spectrum consists of kink-antikink states which are the analogues of mesonic states in QCD, while for q = 3, depending on the sign of the field, the spectrum may also contain three-kink bound states which are the analogues of the baryons. In recent years the resulting "hadron" spectrum was described using several different approaches, such as quantum mechanics in the confining linear potential, WKB methods and also the Bethe-Salpeter equation. Here we compare the available predictions to numerical results from renormalization group improved truncated conformal space approach (RG-TCSA). While mesonic states in the Ising model have already been considered in a different truncated Hamiltonian approach, this is the first time that a precision numerical study is performed for the 3-state Potts model. We find that the semiclassical approach provides a very accurate description for the mesonic spectrum in all the parameter regime for weak magnetic field, while the low-energy expansion from the Bethe-Salpeter equation is only valid for very weak fields where it gives a slight improvement over the semiclassical results. In addition, we confirm the validity of the recent predictions for the baryon spectrum obtained from solving the quantum mechanical three-body problem.Comment: 22 pages, pdflatex source with pdf figures. Version 2: references added, introduction change

Excited state TBA and renormalized TCSA in the scaling Potts model

We consider the field theory describing the scaling limit of the Potts quantum spin chain using a combination of two approaches. The first is the renormalized truncated conformal space approach (TCSA), while the second one is a new thermodynamic Bethe Ansatz (TBA) system for the excited state spectrum in finite volume. For the TCSA we investigate and clarify several aspects of the renormalization procedure and counter term construction. The TBA system is first verified by comparing its ultraviolet limit to conformal field theory and the infrared limit to exact S-matrix predictions. We then show that the TBA and the renormalized TCSA match each other to a very high precision for a large range of the volume parameter, providing both a further verification of the TBA system and a demonstration of the efficiency of the TCSA renormalization procedure. We also discuss the lessons learned from our results concerning recent developments regarding the low-energy scattering of quasi-particles in the quantum Potts spin chain.Comment: 39 pages, 5 eps figures. v2: reference added. v3: several misprints corrected, and an important step in the derivation of counter terms (in section 3.4.1) is explained in more detai

Chiral entanglement in massive quantum field theories in 1+1 dimensions

We determine both analytically and numerically the entanglement between chiral degrees of freedom in the ground state of massive perturbations of 1+1 dimensional conformal field theories quantised on a cylinder. Analytic predictions are obtained from a variational Ansatz for the ground state in terms of smeared conformal boundary states recently proposed by J. Cardy, which is validated by numerical results from the Truncated Conformal Space Approach. We also extend the scope of the Ansatz by resolving ground state degeneracies exploiting the operator product expansion. The chiral entanglement entropy is computed both analytically and numerically as a function of the volume. The excellent agreement between the analytic and numerical results provides further validation for Cardy's Ansatz. The chiral entanglement entropy contains a universal $O(1)$ term $\gamma$ for which an exact analytic result is obtained, and which can distinguish energetically degenerate ground states of gapped systems in 1+1 dimensions.Comment: version 2, references added, minor changes, 31 pages, 12 figures, 6 table

Breather boundary form factors in sine-Gordon theory

A previously conjectured set of exact form factors of boundary exponential operators in the sinh-Gordon model is tested against numerical results from boundary truncated conformal space approach in boundary sine-Gordon theory, related by analytic continuation to sinh-Gordon model. We find that the numerical data strongly support the validity of the form factors themselves: however, we also report a discrepancy in the case of diagonal matrix elements, which remains unresolved for the time being. (C) 2011 Elsevier B.V. All rights reserved

Regularization of multi-soliton form factors in sine-Gordon model

A general and systematic regularization is developed for the exact solitonic form factors of exponential operators in the (1+1)-dimensional sine-Gordon model by analytical continuation of their integral representations. The procedure is implemented in Mathematica. Test results are shown for four- and six- soliton form factors.Comment: 12 pages, no figures. v2: minor corrections, some references adde

Combining textual and graphical modeling with next generation frameworks

Die Kombination von textueller und graphischer Modellierung, d.h. die Darstellung von textuellen Modellen in Form von Diagrammen, ist seit langem ein beliebtes Thema in Model Engineering. Modellierungswerkzeuge bieten den Benutzern oftmals nur die Möglichkeit, Modelle entweder in textueller oder in graphischer Form zu editieren. Bisher wurden Modellierungswerkzeuge, die beide Ansätze kombinieren, nur mit traditionellen Frameworks wie z.B. Xtext und EMF entwickelt. Die Frameworks der nächsten Generation, Langium und die Graphical Language Server Platform (GLSP), bieten neue Möglichkeiten wie erhöhte Modularität in der Architektur und Bereitstellungsoptionen, mehr Flexibilität im Design der Benutzeroberfläche, webbasierte und Cloud-freundliche Entwicklungsmöglichkeiten, während sie die Abhängigkeit von Java eliminieren.Das Ziel dieser Arbeit ist die Kombination von textueller und graphischer Modellierung erneut zu erforschen und weiterzuentwickeln mit den next-generation Frameworks, Langium und GLSP. Es wird ein Konzept für kombinierte textuell-graphische Modellierung auf Basis dieser neuen Frameworks entwickelt, das einen Modellservice nutzt, um die Modifikationsmodelle des textuellen und graphischen Editors gemeinsam zu verwalten. Das Konzept berücksichtigt, dass der grafische und textuelle Editor auf dem gleichen Modell arbeiten müssen, gleichzeitiges Editieren des Modells in beiden Editoren möglich sein muss und nicht-semantische Informationen wie zum Beispiel Kommentare und Formattierungen in der textuellen Darstellung des Modells erhalten bleiben müssen. Das Konzept wird als Artefakt basierend auf der Workflow domänenspezifische Sprache realisiert. Ein bestehendes GLSP-Framework existiert bereits für die Workflow Sprache. Dies wird durch einen Langium-basierten Language Server erweitert, um textuelle Modellierung zu ermöglichen, sowie durch einen Modellserver, der den Zugriff auf das Modell und die Bereitstellung und Updates des Modells zwischen den textuellen und grafischen Editoren verwaltet.Um die entwickelten Konzepte und Artefakte zu evaluieren, werden die implementierten Lösungen auch mit zwei UML-Anwendungsfälle des bigUML Modellierungswerkzeug instantiiert: das Paketdiagramm und das Klassendiagramm. Diese beiden Anwendungsfälle werden gegen die vordefinierten Anforderungen an die textuell-graphische Modellierung evaluiert.Combining textual and graphical modeling i.e., representing textual models in the form of diagrams, has been a popular topic ever since in the field of model engineering. Most often modeling tools only provide users the possibility to create models either in textual form or in the form of a diagram, and the users have to decide upon initial creation of the model whether they would like to use a textual or a graphical model editor. So far, blended modeling tools combining both approaches have only been developed based on traditional frameworks e.g., Xtext and EMF. The next generation frameworks Langium and the Graphical Language Server Platform (GLSP) promote new opportunities such as increased modularity in architecture and deployment options, more flexibility in user interface design, web-based and cloud-friendly development possibilities, while eliminating the dependency to Java.This thesis aims to revisit and explore the topic of combining textual and graphical modeling with the next-generation frameworks Langium and GLSP. A concept for blended textual-graphical modeling based on these frameworks is developed, which utilizes a model service to jointly manage the textual and graphical editor’s underlying modification model. The concept considers that the graphical and textual editor must operate on the same model, simultaneous updates must be possible between the two editors and non-semantic information of the model must be maintained during updates of the model. The concept is realized as an artifact based on the Workflow language. An existing GLSP framework for the Workflow language providing graphical modeling is extended by a Langium language server providing textual modeling, and a model server handling model access, provision and updates between the textual and graphical editors.To evaluate the developed concepts and artifacts, the implemented solution concepts are instantiated by two UML use cases of the bigUML modeling tool: the package diagram and the class diagram. These two use cases are evaluated against the conceptualized requirements of blended textual-graphical modeling

A tápanyagpótlás és gyomirtás értékelése a helyspecifikus növénytermelési technológiában

A Szent István Egyetem Józsefmajori tangazdaságának relatív jó talajadottságokkal rendelkező tábláiban a precíziós tápanyagpótlás alkalmazásával akár hektáronként 60 kg nitrogénhatóanyag-megtakarítás is elvárható a konvencionális technológiához képest. A precíziós tápanyagpótlási technológiával, a vizsgált táblák 50%-ánál tapasztalható anyagköltség-megtakarítás. Az anyagmegtakarítás mellett célszerű számolni a működési költségek növekedésével. A Szegedi Gabonakutató Kft. segítségével végzett szántóföldi kísérletek adatai alapján megállapítható, hogy kukoricatermelésnél 48,85% őszi gyomborítottság felett ökonómiailag indokolt a precíziós gyomirtás. ----------------------------------- By applying precision nutrient supplementation rather instead of conventional technology, as much as 60 kg of nitrogen active substance can be saved per hectare in the Józsefmajor study farm of Szent István University, which has relatively good soil. Precision nutrient supplementation enabled lower material costs in 50% of the parcels studied, provided that parcel level yield potential was ignored. In addition to saving on materials, though, increased operating costs should also be taken into consideration. Field tests performed with the assistance of Szegedi Gabonakutató Kft. showed that in maize production, precision weed control was economically justifi ed when autumn weed coverage exceeded 48.85%

Technologie rolnictwa precyzyjnego i motywujące czynniki adaptacyjne

Thanks to precision farming technology, farmers are able to optimise input in the field with management-zones. Management-zones (the smallest treatment unit in the field) are defined on the basis of knowledge of local conditions, e.g. physical and chemical soil conditions, soil productivity, the presence of weeds and/or pests as well as the incidence of disease. Precision farming technology is able to materialize the requirements of sustainability and increase production. The application of precision farming technology elements go hand in hand with extra costs (the investment costs of new equipment and software; higher operating costs), simultaneously decreasing material costs (the costs of nutrition, herbicides, seeds). The aim of this study is to define motivation factors standing behind the adaptation of precision farming technology. According to 11% of interviewed farmers using precision farming technology on their farms and the research conducted, the main factors of adaptation were field quantity and the age of the farmer.Celem badań było określenie czynników motywujących do wdrażania technologii rolnictwa precyzyjnego. Technologia rolnictwa precyzyjnego za pomocą stref zarządzania pozwala rolnikom optymalizować poziom ponoszonych nakładów. Podstawą do wyznaczenia stref zarządzania (najmniejszej jednostki pola podlegającej obróbce) jest wiedza na temat lokalnych warunków, np. fizycznych i chemicznych właściwości gleby, zachwaszczenia, występowania szkodników i chorób oraz produktywności gleby. Technologia rolnictwa precyzyjnego jest w stanie urzeczywistnić wymogi ochrony środowiska, zwiększając jednocześnie efektywność produkcji. Stosowanie elementów technologii rolnictwa precyzyjnego wiąże się z dodatkowymi kosztami w inwestowanie w nowy sprzęt i oprogramowanie, a także z wyższymi kosztami operacyjnymi, przy mniejszych wydatkach na materiały (koszt żywienia, herbicydów, nasion). Wśród ankietowanych 11% stosowało technologie rolnictwa precyzyjnego i głównym czynnikiem jej adaptacji była wielkość pola oraz wiek rolnika