789 research outputs found

    On Maximum Signless Laplacian Estrada Indices of Graphs with Given Parameters

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    Signless Laplacian Estrada index of a graph GG, defined as SLEE(G)=∑i=1neqiSLEE(G)=\sum^{n}_{i=1}e^{q_i}, where q1,q2,⋯ ,qnq_1, q_2, \cdots, q_n are the eigenvalues of the matrix Q(G)=D(G)+A(G)\mathbf{Q}(G)=\mathbf{D}(G)+\mathbf{A}(G). We determine the unique graphs with maximum signless Laplacian Estrada indices among the set of graphs with given number of cut edges, pendent vertices, (vertex) connectivity and edge connectivity.Comment: 14 pages, 3 figure

    The Parametric Generalized Fractional Nikiforov-Uvarov Method and Its Applications

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    By using generalized fractional derivative, the parametric generalized fractional Nikiforov-Uvarov (NU) method is introduced. The second-order parametric generalized differential equation is exactly solved in the fractional form. The obtained results are applied on the extended Cornell potential, the pesudoharmonic potential, the Mie potential, the Kratzer-Fues potential, the harmonic oscillator potential, the Morse potential, the Woods-Saxon potential, the Hulthen potential, the deformed Rosen-Morse potential and the Poschl-Teller potential which play an important role in the fields of molecular and hadron physics. The special classical cases are obtained from the fractional cases at ELFA = BETA =1 which are agreements with recent works.Comment: 15 page

    Properties and Behaviors of Heavy Quarkonia: Insights Through Fractional Model and Topological Defects

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    In this study, we investigated the impact of a topological defect on the properties of heavy quarkonia using the extended Cornell potential. We solved the fractional radial Schrodinger equation (SE) using the extended Nikorov-Uvarov (ENU) method to obtain the eigen energy, which allowed us to calculate the masses of charmonium and bottomonium. One significant observation was the splitting between np and nd states, which we attributed to the presence of the topological defect. We discovered that the excited states were divided into components corresponding to 2l + 1, indicating that the gravity field induced by the topological defect interacts with energy levels in a manner similar to the Zeeman effect caused by a magnetic field. Additionally, we derived the wave function and calculated the root mean radii for charmonium and bottomonium. A comparison with classical models was performed, resulting in better results being obtained. Furthermore, we investigated the thermodynamic properties of charmonium and bottomonium, determining quantities such as energy, partition function, free energy, mean energy, and specific heat for p-states. The obtained results were found to be consistent with experimental data and previous works. In conclusion, the fractional model used in this work proved essential in understanding the various properties and behaviors of heavy quarkonia in the presence of topological defects.Comment: 29 pages, 13 figures, 6 Table

    The Effect of Extended Cornell Potential on Heavy and Heavy-Light Meson Masses Using Series Method

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    The effect of an extended Cornell potential on the mass spectra of heavy and heavy-light mesons is studied. The Cornell potential is extended to include quadratic potential and inverse quadratic potential. The N-radial Schrödinger equation is solved by using series method. The results for charmonium and bottomonium and light-heavy meson masses are obtained. A comparison with other recent works is discussed. The present results are improved in comparison with other recent works and are in a good agreement with experimental data

    Spectra of Heavy Quarkonia in a Magnetized-Hot Medium in the Framework of Fractional Non-relativistic Quark Model

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    In the fractional nonrelativistic potential model, the decomposition of heavy quarkonium in a hot magnetized medium is investigated. The analytical solution of the fractional radial Schrodinger equation for the hot-magnetized interaction potential is displayed by using the conformable fractional Nikiforov-Uvarov method. Analytical expressions for the energy eigenvalues and the radial wave function are obtained for arbitrary quantum numbers. Next, we study the charmonium and bottmonium binding energies for different magnetic field values in the thermal medium. The effect of the fractional parameter on the decomposition temperature is also analyzed for charmonium and bottomonium in the presence of hot magnetized media. We conclude that the dissociation of heavy quarkonium in the fractional nonrelativistic potential model is more practical than the classical nonrelativistic potential model.Comment: 13 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:2104.0054

    IJMC Computing Chemical Properties of Molecules by Graphs and Rank Polynomials

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    ABSTRACT The topological index of a graph G is a numeric quantity related to G which is invariant under automorphisms of G. The Tutte polynomial of is a polynomial in two variables defined for every undirected graph contains information about connectivity of the graph. The Padmakar-Ivan, vertex Padmakar-Ivan polynomials of a graph are polynomials in one variable defined for every simple connected graphs that are undirected. In this paper, we compute these polynomials of two infinite classes of dendrimer nanostars

    Measuring system resilience through a comparison of information- and flow-based network analyses

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    Quantifying the properties of complex, self-organizing systems is increasingly important for understanding the development and state of modern systems. Case studies have recommended sustainability frameworks predominately in literature, but little emphasis has been placed on methodological evaluation. Data availability is often an obstacle that constrains conventional flow-based network analysis, but a novel information-based technique (QtAC) developed by zu Castell and Schrenk overcomes these constraints by modelling interactions between agents as information transfers. This study compares the QtAC method to conventional flow analysis by applying both to the same 90-year dataset containing socio-economic data from the island of Samothraki, Greece. Resilience indicators, based on Ulanowicz's ascendency analysis, are derived on both the information- and flow-based networks. We observe that the resulting dynamics of the information-based networks align closer with complex system dynamics as theorized by the adaptive cycle model. Additionally, we discuss how QtAC offers different interpretations of network indicators when compared to usual interpretations of flow analysis. Ultimately, QtAC is shown to provide an alternative for complex systems analysis if the data situation does not allow for conventional flow-analysis. Furthermore, we show that the combination of both approaches can yield valuable new insights

    Modelling stakeholder satisfaction for conflict resolution in wildlife management: a case of wolf population in Sweden

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    The Swedish wolf population has rebounded from near extinction in the 1960s to around 365 individuals in 2020, after the implementation of the Hunting Act (jaktlagen) in 1966. This recent increase in the wolf population has evoked a serious divide between “pro-wolf” and “anti-wolf” Swedish citizens. Despite the continuous efforts by the Swedish government to reconcile this antagonism, the conflicts are persistent with a sign of impasse. In this paper, we present a modelling tool, which can bring transparent and “structured dialogue to the opposing positions.” This approach includes a stylized framework for quantitative modelling of stakeholders’ satisfaction levels regarding their preferred size of the wildlife population in question, based on the concept of satisfaction functions. We argue that this framework may contribute to conflict resolution by bringing a common understanding among stakeholders, facilitate a societal discourse, and potentially help to assess likely support for conservation policies. We present a showcase application of this modeling tool in the context of the conflict over the Swedish wolf conservation policies. The model is informed using a thorough literature review as well as interviews, which identified relevant stakeholder groups and respective drivers of their attitudes towards wolves

    Global Urban Carbon Networks: Linking Inventory to Modeling

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    Cities utilize and manipulate an immense amount of global carbon flows through their economic and technical activities. Here, we establish the carbon networks of eight global cities by tracking the carbon exchanges between various natural and economic components. The metabolic properties of these carbon networks are compared by combining flow-based and interpretative network metrics. We further assess the relations of these carbon metabolic properties of cities with their socioeconomic attributes that are deemed important in urban development and planning. We find that, although there is a large difference in city-level carbon balance and flow pattern, a similarity in intercomponent relationships and metabolic characteristicsdoes exist. Cities with lower per capita carbon emissions tend to have healthier metabolic systems with more cooperative resource allocation among various industries, which indicates that there may be synergy between urban decarbonization and carbon-containing resource system optimization. A combination of indicators from flow balance and network models is a promising scheme for linking sector-based carbon inventories to system-based simulations of carbon management efforts. With this done, we may be able to reduce the knowledge gap with respect to how various carbon flows in cities can be concertedly managed considering both the restraint from their climate mitigation goals as well as the impact on urban social and economic development

    A numerical method for detecting incommensurate correlations in the Heisenberg zigzag ladder

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    We study two Heisenberg spin-1/2 chains coupled by a frustrating ``zigzag'' interaction. We are particularly interested in the regime of weak interchain coupling, which is difficult to analyse by either numerical or analytical methods. Previous density matrix renormalisation group (DMRG) studies of the isotropic model with open boundary conditions and sizeable interchain coupling have established the presence of incommensurate correlations and of a spectral gap. By using twisted boundary conditions with arbitrary twist angle, we are able to determine the incommensurabilities both in the isotropic case and in the presence of an exchange anisotropy by means of exact diagonalisation of relatively short finite chains of up to 24 sites. Using twisted boundary conditions results in a very smooth dependence of the incommensurabilities on system size, which makes the extrapolation to infinite systems significantly easier than for open or periodic chains.Comment: 6 pages, including 7 figure
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