17,358 research outputs found
BPS States on M5-brane in Large C-field Background
We extensively study BPS solutions of the low energy effective theory of
M5-brane in large C-field background. This provides us an opportunity to
explore the interactions turned on by C-field background through the
Nambu-Poisson structure. The BPS states considered in this paper include the
M-waves, the self-dual string (M2 ending on M5), tilted M5-brane, holomorphic
embedding of M5-brane and the intersection of two M5-branes along a 3-brane.Comment: 25 pages, reference adde
N = 2 SCFTs: An M5-brane perspective
Inspired by the recently discovered holographic duality between N=2 SCFTs and
half-BPS M-theory backgrounds, we study probe M5-branes. Though our main focus
is supersymmetric M5-branes whose worldvolume has an AdS_n factor, we also
consider some other configurations. Of special mention is the identification of
AdS_5 and AdS_3 probes preserving supersymmetry, with only the latter
supporting a self-dual field strength.Comment: 27 page
Bounded Verification with On-the-Fly Discrepancy Computation
Simulation-based verification algorithms can provide formal safety guarantees
for nonlinear and hybrid systems. The previous algorithms rely on user provided
model annotations called discrepancy function, which are crucial for computing
reachtubes from simulations. In this paper, we eliminate this requirement by
presenting an algorithm for computing piece-wise exponential discrepancy
functions. The algorithm relies on computing local convergence or divergence
rates of trajectories along a simulation using a coarse over-approximation of
the reach set and bounding the maximal eigenvalue of the Jacobian over this
over-approximation. The resulting discrepancy function preserves the soundness
and the relative completeness of the verification algorithm. We also provide a
coordinate transformation method to improve the local estimates for the
convergence or divergence rates in practical examples. We extend the method to
get the input-to-state discrepancy of nonlinear dynamical systems which can be
used for compositional analysis. Our experiments show that the approach is
effective in terms of running time for several benchmark problems, scales
reasonably to larger dimensional systems, and compares favorably with respect
to available tools for nonlinear models.Comment: 24 page
M2-M5 blackfold funnels
We analyze the basic M2-M5 intersection in the supergravity regime using the
blackfold approach. This approach allows us to recover the 1/4-BPS self-dual
string soliton solution of Howe, Lambert and West as a three-funnel solution of
an effective fivebrane worldvolume theory in a new regime, the regime of a
large number of M2 and M5 branes. In addition, it allows us to discuss finite
temperature effects for non-extremal self-dual string soliton solutions and
wormhole solutions interpolating between stacks of M5 and anti-M5 branes. The
purpose of this paper is to exhibit these solutions and their basic properties.Comment: 19 pages, 5 figures, harvmac; typo corrected in equation (3.19
More on the Nambu-Poisson M5-brane Theory: Scaling limit, background independence and an all order solution to the Seiberg-Witten map
We continue our investigation on the Nambu-Poisson description of M5-brane in
a large constant C-field background (NP M5-brane theory) constructed in
Refs.[1, 2]. In this paper, the low energy limit where the NP M5-brane theory
is applicable is clarified. The background independence of the NP M5-brane
theory is made manifest using the variables in the BLG model of multiple
M2-branes. An all order solution to the Seiberg-Witten map is also constructed.Comment: expanded explanations, minor corrections and typos correcte
The systemic distribution of Epstein-Barr virus genomes in fatal post-transplantation lymphoproliferative disorders: An in situ hybridization study
The systemic distribution of Epstein-Barr virus (EBV) genomes was studied in paraffin-embedded tissues from 12 fatal cases of Post-transplantation lymphoproliferative disease (PTLD), using an in situ hybridization technique employing an alpha-35S-dCTP-radiolabeled BamHI-W fragment of EBV DNA. The presence of EBV was documented in various PTLD-involved organs. The hybridization signal for the virus localized predominantly in the abnormal lymphoid cells, but signals also were detected in hepatocytes and/or adrenal cortical cells in five cases. The distribution of autoradiographic label within the lymphoid cells was focal and its intensity varied from field to field, suggesting a nonuniformity of the viral genomic load in the infected tissues. Recruitment of EBV genome-bearing cells was not observed into inflammatory mononuclear infiltrates found in organs without histopathologic evidence of PTLD
Speciation and fate of copper in sewage treatment works with and without tertiary treatment: The effect of return flows
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Taylor & Francis.The removal of metals from wastewaters is becoming an important issue, with new environmental quality standards putting increased regulatory pressure on operators of sewage treatment works. The use of additional processes (tertiary treatment) following two-stage biological treatment is frequently seen as a way of improving effluent quality for nutrients and suspended solids, and this study investigates the impact of how back washes from these tertiary processes may impact the removal of copper during primary sedimentation. Seven sites were studied, three conventional two-stage biological treatment, and four with tertiary processes. It was apparent that fluxes of copper in traditional return flows made a significant contribution to the load to the primary treatment tanks, and that<1% of this was in the dissolved phase. Where tertiary processes were used, back wash liquors were also returned to the primary tanks. These return flows had an impact on copper removal in the primary tanks, probably due to their aerobic nature. Returning such aerobic back wash flows to the main process stream after primary treatment may therefore be worth consideration. The opportunity to treat consolidated liquor and sludge flows in side-stream processes to remove toxic elements, as they are relatively concentrated, low volume flow streams, should also be evaluated
The removal of thermally aged films of triacylglycerides by surfactant solutions
Thermal ageing of triacylglycerides (TAG) at high temperatures produces films which resist removal using aqueous surfactant solutions. We used a mass loss method to investigate the removal of thermally aged TAG films from hard surfaces using aqueous solutions of surfactants of different charge types. It was found that cationic surfactants are most effective at high pH, whereas anionics are most effective at low pH and a non-ionic surfactant is most effective at intermediate pH. We showed that the TAG film removal process occurs in several stages. In the first ‘‘lag phase’’ no TAG removal occurs; the surfactant first partitions into the thermally aged film. In the second stage, the TAG film containing surfactant was removed by solubilisation into micelles in the aqueous solution. The effects of pH and surfactant charge on the TAG removal process correlate with the effects of these variables on the extent of surfactant partitioning to the TAG film and on the maximum extent of TAG solubilisation within the micelles. Additionally, we showed how the TAG removal is enhanced by the addition of amphiphilic additives such as alcohols which act as co-surfactants. The study demonstrates that aqueous surfactant solutions provide a viable and more benign alternative to current methods for the removal of thermally aged TAG films
Further detections of OH masers in carbon stars with silicate features
A sample of J-type carbon stars was searched for OH maser emission. The new
detection of three OH lines towards two silicate carbon stars is reported. In
V778 Cyg, previously known as the main-lines (1665 and 1667 MHz) maser source,
the satellite 1612 MHz emission was discovered while in NSV 2814 the main OH
lines were detected. The presence of OH maser lines confirms the former
suggestion that oxygen-rich material is located in the vicinity (
cm) of silicate carbon stars.Comment: LaTeX2e, 4 pages with 2 figure
Deformed Quantum Cohomology and (0,2) Mirror Symmetry
We compute instanton corrections to correlators in the genus-zero topological
subsector of a (0,2) supersymmetric gauged linear sigma model with target space
P1xP1, whose left-moving fermions couple to a deformation of the tangent
bundle. We then deduce the theory's chiral ring from these correlators, which
reduces in the limit of zero deformation to the (2,2) ring. Finally, we compare
our results with the computations carried out by Adams et al.[ABS04] and Katz
and Sharpe[KS06]. We find immediate agreement with the latter and an
interesting puzzle in completely matching the chiral ring of the former.Comment: AMSLatex, 30 pages, one eps figure. V4: typos corrected, final
version appearing in JHE
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