983 resultados para Toda lattice hierarchy


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We derive the formal Ward identities relating pseudoscalar susceptibilities and quark condensates in three-flavor QCD, including consistently the 77-n' sector and the U-A(1) anomaly. These identities are verified in the low-energy realization provided by ChPT, both in the standard SU(3) framework for the octet case and combining the use of the SU(3) framework and the large-Nc expansion of QCD to account properly for the nonet sector and anomalous contributions. The analysis is performed including finite temperature corrections as well as the calculation of U(3) quark condensates and all pseudoscalar susceptibilities, which together with the full set of Ward identities, are new results of this work. Finally, the Ward identities are used to derive scaling relations for pseudoscalar masses which explain the behavior with temperature of lattice screening masses near chiral symmetry restoration.

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We propose a realistic scheme to quantum simulate the so-far experimentally unobserved topological Mott insulator phase-an interaction-driven topological insulator-using cold atoms in an optical Lieb lattice. To this end, we study a system of spinless fermions in a Lieb lattice, exhibiting repulsive nearest-and next-to-nearest-neighbor interactions and derive the associated zero-temperature phase diagram within mean-field approximation. In particular, we analyze how the interactions can dynamically generate a charge density wave ordered, a nematic, and a topologically nontrivial quantum anomalous Hall phase. We characterize the topology of the different phases by the Chern number and discuss the possibility of phase coexistence. Based on the identified phases, we propose a realistic implementation of this model using cold Rydberg-dressed atoms in an optical lattice. The scheme, which allows one to access, in particular, the topological Mott insulator phase, robustly and independently of its exact position in parameter space, merely requires global, always-on off-resonant laser coupling to Rydberg states and is feasible with state-of-the-art experimental techniques that have already been demonstrated in the laboratory.

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El fútbol es el deporte rey en España. Los clubes nacionales siempre han cosechado grandes triunfos en Europa y en el mundo. Sin embargo, la selección española, históricamente, ha sido una decepción en todas las competiciones en las que participaba, en las que no lograba llegar a las finales, solo en la Eurocopa de 2008 y en pocas ocasiones más lo logró. Millones de personas iban a estar pendientes de Sudáfrica durante un mes: desde el 11 de junio, hasta el 11 de julio de 2010. Medios de comunicación de todo el globo desplegaron equipos a la zona para cubrir el evento futbolístico más importante del mundo. Tras la victoria española en 2008, la expectación por ver qué papel haría la selección en este Mundial aumentó considerablemente y, esta vez sí, aseguraban muchos, España podía volver con la Copa a casa. La prensa deportiva madrileña, Marca y As, tenía que hacer frente a la ilusión generada en la sociedad española, y el interés que por ello se despertaba en una época nada fácil, en la cual la crisis comenzaba ya a hacer mella en la población que utilizaba el fútbol, en muchos casos, para evadirse de los problemas. “Si no hubiera fútbol, la crisis la viviríamos con más tensión o de una forma más obsesiva”, asegura Santiago Álvarez de Món, profesor de la prestigiosa Escuela de Negocios IESE. “Sinceramente, prefiero una sociedad con fútbol que sin él. Al fin y al cabo, este deporte es un estado de ánimo”, dice este docente. Una sensación de euforia que se intensifica con las recientes victorias de la Selección Española, señala Miguel Ángel García Vega, autor del artículo “El fútbol, balón de oxígeno social”...

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This paper shows, by means of Kronecker’s theorem, the existence of infinitely many privileged regions called r -rectangles (rectangles with two semicircles of small radius r ) in the critical strip of each function Ln(z):= 1−∑nk=2kz , n≥2 , containing exactly [Tlogn2π]+1 zeros of Ln(z) , where T is the height of the r -rectangle and [⋅] represents the integer part.

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The aim of this report is to discuss the method of determination of lattice-fluid binary interaction parameters by comparing well characterized immiscible blends and block copolymers of poly(methyl methacrylate) (PMMA) and poly(ϵ−caprolactone) (PCL). Experimental pressure-volume-temperature (PVT) data in the liquid state were correlated with the Sanchez—Lacombe (SL) equation of state with the scaling parameters for mixtures and copolymers obtained through combination rules of the characteristic parameters for the pure homopolymers. The lattice-fluid binary parameters for energy and volume were higher than those of block copolymers implying that the copolymers were more compatible due to the chemical links between the blocks. Therefore, a common parameter cannot account for both homopolymer blend and block copolymer phase behaviors based on current theory. As we were able to adjust all data of the mixtures with a single set of lattice-binary parameters and all data of the block copolymers with another single set we can conclude that both parameters did not depend on the composition for this system. This characteristic, plus the fact that the additivity law of specific volumes can be suitably applied for this system, allowed us to model the behavior of the immiscible blend with the SL equation of state. In addition, a discussion on the relationship between lattice-fluid binary parameters and the Flory–Huggins interaction parameter obtained from Leibler's theory is presented.

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Drawing heavily on the work of classicist Page duBois, which eloquently explains the emergence, in ancient Greece, of hierarchy and of what is still understood today as the great chain of being (scala naturae: male, female, slave, barbarian, animal), this paper analyzes the age-old negative conotations of the concept of difference in western culture, considers the reinvention of difference as “positive” by Rosi Braidotti (after Deleuze & Guattari), and reassesses the efforts of several other feminist philosophers (e.g. Luce Irigaray, Judith Butler, Gayatry Spivak, Drucilla Cornell) to counter Lacan on the impossibility of “speaking women” beyond the dominant (male) philosophical discourse. Or, to paraphrase Marie Cardinal, their efforts to find “les mots pour le dire”.

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Existing studies focus on overall support for European integration while less work has been done on explaining public opinion on specific policy areas, such as the development of the Common Security and Defense Policy (CSDP). We hypothesize that the probability of supporting a CSDP increases with greater levels of trust in the European Union member states, most notably the more powerful members. This variable is critical since integration’s development is influenced strongly by, and dependent on, the resources of the relatively more powerful European member states. Binary logistic regression analyses using pooled repeated cross-sectional data from the Eurobarometer surveys conducted from 1992 to 1997 among individuals of 11 member states largely support these claims.

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Proof-theoretic methods are developed and exploited to establish properties of the variety of lattice-ordered groups. In particular, a hypersequent calculus with a cut rule is used to provide an alternative syntactic proof of the generation of the variety by the lattice-ordered group of automorphisms of the real number chain. Completeness is also established for an analytic (cut-free) hypersequent calculus using cut elimination and it is proved that the equational theory of the variety is co-NP complete.