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...nd three dimensions we find new fixed points with exceptional symmetries. August 19961. Introduction It is becoming clear that there is an interesting relation between quantum field theory on branes =-=[1]-=- and space-time dynamics in string theory [1-6]. This relation generalizes the more standard world-sheet/space-time relation. It is particularly interesting when the theory on the brane is a non-trivi...

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...sm [43]. That is there can be a term in the Kahler potential, ∫ d 4 θΣH1H2/MPl, where Σ is a singlet which breaks supersymmetry. 3. CP is generally a problem, without additional symmetries. (See Ref. =-=[44]-=- and references therein.) 44. When the above problems are not solved, the theory appears simple; however attempts to address these inadequacies necessarily lead to more complicated models. 5. Until w...

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...lute alkali gases. These interactions are well described in a mean-field model by a self-interaction energy that depends only on the density of the condensate (n) and the s-wave scattering length (a) =-=[1]-=-. Strong repulsive interactions produce stable condensates with a size and shape determined by the self-interaction energy. In contrast, attractive interactions (a < 0) lead to a condensate state wher...

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... equimolar quan-sEuglossine bees (Euplusia, Eulaema,sEuglossa) are important pollinators ofslowland neotropical woody plants (1,s2). There have been mnany studies ofstheir nesting and social behavior =-=(2)-=-sand on the obligatory mutualistic inter-saction between euglossine males and thesorchids they pollinate (3). The spec-stacular pollination activities of thesmales are probably of much less im-sportan...

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... best of our knowledge, they are the first examples of shape invariance discussed in the framework of discrete quantum mechanics. Of course there are plenty of works applying the factorisation method =-=[12, 13, 14]-=- to various difference equations [15, 16]. However, all of these difference equations contain finite shifts in the real direction, which result in polynomials of a discrete variable, for example the C...

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...symmetry. Hypermultiplets and vector multiplets contribute with opposite signs. Also, as explained in [7] this quantity has a natural interpretation in terms of the physics of branes in string theory =-=[10]-=-. In all of these cases, the sign of c is of crucial importance for the behavior of the theory. In four dimensions, c coincides with the coefficient of the one loop beta function. Therefore, its sign ...

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...ole of the Sugawara construction in Chern-Simons theory was first found in [3]. 16The quantization of the Virasoro algebra has been extensively studied in the literature. We refer the reader to Ref. =-=[13]-=- for details. We define the quantum Virasoro operator ˆLn = β : Ln : + aδn (56) where :: means normal order. The constant β and a are given by β = 2k 1 , a = 2k + Q 2 kα2β(β − 1), (57) and Qg ad = f a...

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...st their properties. 4.1 Eternal inflation The hypothesis of early universe inflation gives a plausible explanation of several observed features of our universe, such as its homogeneity and uniformity=-=[18, 19]-=-. The basic idea is that at very early times the energy density is dominated by a large vacuum energy, possibly coming from the vacuum expectation value of a scalar field. As the universe expands expo...