9,297 research outputs found
Delocalized, non-SUSY -branes, tachyon condensation and tachyon matter
We construct non-supersymmetric -brane solutions of type II supergravities
in arbitrary dimensions () delocalized in one of the spatial transverse
directions. By a Wick rotation we convert these solutions into Euclidean
-branes delocalized in the transverse time-like direction. The former
solutions in nicely interpolate between the -dimensional non-BPS
D-branes and the -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
-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
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 -branes in diverse dimensions
We give explicit constructions of static, non-supersymmetric -brane (for
, where is the space-time dimensionality and including
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 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 -brane--anti -brane solutions and the usual BPS -brane
solutions in , 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 -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
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
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
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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