43,848 research outputs found

    A Mathematical Model of the Obesity Epidemic

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    Critical phenomena of the Majority voter model in a three dimensional cubic lattice

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    In this work we investigate the critical behavior of the three dimensional simple-cubic Majority voter model. Using numerical simulations and a combination of two different cumulants we evaluated the critical point with a higher accuracy than the previous numerical result found by Yang et al. [J.- S. Yang, I.-M. Kim and W. Kwak, Phys. Rev. E 77, 051122 (2008)]. Using standard Finite Size Scaling theory and scaling corrections we find that the critical exponents {\nu}, {\gamma} and {\beta} are the same as those of the three dimensional Ising model.Comment: 5 pages, 5 figures. Accepted in PR

    Surveying the quantum group symmetries of integrable open spin chains

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    Using anisotropic R-matrices associated with affine Lie algebras g^\hat g (specifically, A2n(2),A2n−1(2),Bn(1),Cn(1),Dn(1)A_{2n}^{(2)}, A_{2n-1}^{(2)}, B_n^{(1)}, C_n^{(1)}, D_n^{(1)}) and suitable corresponding K-matrices, we construct families of integrable open quantum spin chains of finite length, whose transfer matrices are invariant under the quantum group corresponding to removing one node from the Dynkin diagram of g^\hat g. We show that these transfer matrices also have a duality symmetry (for the cases Cn(1)C_n^{(1)} and Dn(1)D_n^{(1)}) and additional Z2Z_2 symmetries that map complex representations to their conjugates (for the cases A2n−1(2),Bn(1),Dn(1)A_{2n-1}^{(2)}, B_n^{(1)}, D_n^{(1)}). A key simplification is achieved by working in a certain "unitary" gauge, in which only the unbroken symmetry generators appear. The proofs of these symmetries rely on some new properties of the R-matrices. We use these symmetries to explain the degeneracies of the transfer matrices.Comment: 48 page

    On the scaling rules for the anomaly-induced effective action of metric and electromagnetic field

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    The anomaly-induced effective action is a useful tool for deriving the contributions coming from quantum effects of massless conformal fields. It is well-known that such corrections in the higher derivative vacuum sector of the gravitational action provide the same exponential inflation (Starobinsky model) as the cosmological constant term. At the same time, the presence of a classical electromagnetic field breaks down the exponential solution. In this paper we explore the role of the anomaly-induced term in the radiation sector and, furthermore, derive the ``equation of state'' and the scaling laws for all terms in the Einstein equations. As one could expect, the scaling law for the vacuum anomaly-induced effective action is the same as for the cosmological constant.Comment: 12 pages, LaTeX, 4 figure

    The World War II Patriotic Mother

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    The archetypal good mother and the archetypal patriotic mother are important symbols in American culture. Both are rooted in maternal work but are separated by two conflicting assumptions. The good mother nurtures her children and protects them from harm, while the patriotic wartime mother remains silent when the government sends her child directly into harm\u27s way. This study explores how the World War II press positioned mothers of soldiers to sacrifice their children in support of the nation\u27s war effort. The findings point to the importance of understanding the role of archetypes in news narratives

    Patriotic Motherhood and the Iraq War

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    She plays a familiar character in our nation\u27s war stories and she has a warm place in our nation\u27s heart. She is the patriotic mother, a cultural symbol of bravery and sacrifice, stoicism and silence. Her image may reflect our historical understanding of the mothers of combat soldiers, but the story the national press tells about the mothers of U.S. soldiers in the Iraq War does not quite match these cultural expectations

    The spectrum of quantum-group-invariant transfer matrices

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    Integrable open quantum spin-chain transfer matrices constructed from trigonometric R-matrices associated to affine Lie algebras g^\hat g, and from certain K-matrices (reflection matrices) depending on a discrete parameter p, were recently considered in arXiv:1802.04864 and arXiv:1805.10144. It was shown there that these transfer matrices have quantum group symmetry corresponding to removing the p-th node from the g^\hat g Dynkin diagram. Here we determine the spectrum of these transfer matrices by using analytical Bethe ansatz, and we determine the dependence of the corresponding Bethe equations on p. We propose formulas for the Dynkin labels of the Bethe states in terms of the numbers of Bethe roots of each type.We also briefly study how duality transformations are implemented on the Bethe ansatz solutions.Comment: 37 page
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