9,297 research outputs found

    Delocalized, non-SUSY pp-branes, tachyon condensation and tachyon matter

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    We construct non-supersymmetric pp-brane solutions of type II supergravities in arbitrary dimensions (dd) delocalized in one of the spatial transverse directions. By a Wick rotation we convert these solutions into Euclidean pp-branes delocalized in the transverse time-like direction. The former solutions in d=10d=10 nicely interpolate between the (p+1)(p+1)-dimensional non-BPS D-branes and the pp-dimensional BPS D-branes very similar to the picture of tachyon condensation for the tachyonic kink solution on the non-BPS D-branes. On the other hand the latter solutions interpolate between the (p+1)(p+1)-dimensional non-BPS D-branes and the tachyon matter supergravity configuration very similar to the picture of rolling tachyon on the non-BPS D-branes.Comment: 15 pages, typos correcte

    Chimera states in a population of identical oscillators under planar cross-coupling

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    We report the existence of a chimera state in an assembly of identical nonlinear oscillators that are globally linked to each other in a simple planar cross-coupled form. The rotational symmetry breaking of the coupling term appears to be responsible for the emergence of these collective states that display a characteristic coexistence of coherent and incoherent behaviour. Our finding, seen in both a collection of van der Pol oscillators and chaotic Rossler oscillators, further simplifies the existence criterion for chimeras and thereby broadens the range of their applicability to real world situations

    Static, non-SUSY pp-branes in diverse dimensions

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    We give explicit constructions of static, non-supersymmetric pp-brane (for pd4p \leq d-4, where dd is the space-time dimensionality and including p=1p=-1 or D-instanton) solutions of type II supergravities in diverse dimensions. A subclass of these are the static counterpart of the time dependent solutions obtained in [hep-th/0309202]. Depending on the forms of the non-extremality function G(r)G(r) defined in the text, we discuss various possible solutions and their region of validity. We show how one class of these solutions interpolate between the pp-brane--anti pp-brane solutions and the usual BPS pp-brane solutions in d=10d=10, while the other class, although have BPS limits, do not have such an interpretation. We point out how the time dependent solutions mentioned above can be obtained by a Wick rotation of one class of these static solutions. We also discuss another type of solutions which might seem non-supersymmetric, but we show by a coordinate transformation that they are nothing but the near horizon limits of the various BPS pp-branes already known.Comment: 29 pages, typos corrected, references adde

    The Schwinger SU(3) Construction - II: Relations between Heisenberg-Weyl and SU(3) Coherent States

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    The Schwinger oscillator operator representation of SU(3), studied in a previous paper from the representation theory point of view, is analysed to discuss the intimate relationships between standard oscillator coherent state systems and systems of SU(3) coherent states. Both SU(3) standard coherent states, based on choice of highest weight vector as fiducial vector, and certain other specific systems of generalised coherent states, are found to be relevant. A complete analysis is presented, covering all the oscillator coherent states without exception, and amounting to SU(3) harmonic analysis of these states.Comment: Latex, 51 page

    Fermion- and spin-counting in strongly correlated systems in and out of thermal equilibrium

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    Atom counting theory can be used to study the role of thermal noise in quantum phase transitions and to monitor the dynamics of a quantum system. We illustrate this for a strongly correlated fermionic system, which is equivalent to an anisotropic quantum XY chain in a transverse field, and can be realized with cold fermionic atoms in an optical lattice. We analyze the counting statistics across the phase diagram in the presence of thermal fluctuations, and during its thermalization when the system is coupled to a heat bath. At zero temperature, the quantum phase transition is reflected in the cumulants of the counting distribution. We find that the signatures of the crossover remain visible at low temperature and are obscured with increasing thermal fluctuations. We find that the same quantities may be used to scan the dynamics during the thermalization of the system.Comment: 10 pages, 7 figure

    Dynamics of Sclerotium rolfsii as influenced by different crop rhizosphere and microbial community

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    This study was carried out with the aim of evaluating pathogenicity of Sclerotium rolfsii to different crops influenced by different crop rhizosphere microbes and their population dynamics. Napier was found to be non-preferred host against S. rolfsii pathogen. Among the seven tested crops in micro-plot study, highest level of induction of sclerotial population was observed in groundnut and cow peas (21.81 and 20.06 numbers of sclerotia /100 g of soil, respectively), whereas, reduction in sclerotial number was observed in napier, maize and sorghum plots. S. rolfsii induced damping off was found to be significantly positively correlated with average sclerotial population irrespective of plant cover even at 1% level of significance (r = 0.985) and among the microbiological parameters, FDA was found to be significantly negatively correlated with damping off disease percentage at 5% level of significance (r = - 0.830). Therefore, Napier may be the potential crop to be incorporated in the sequence of rice/vegetable based cropping system in West Bengal for management of this dreaded pathogen
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