7,040 research outputs found
A Prediction of Observable Rotation in the ICM of Abell 3266
We present a numerical Hydro+N-body model of A3266 whose X-ray surface
brightness, temperature distribution, and galaxy spatial and velocity
distribution data are consistent with the A3266 data. The model is an old (~3
Gyr), off-axis merger having a mass ratio of ~2.5:1. The less massive
subcluster in the model is moving on a trajectory from southwest to northeast
passing on the western side of the dominant cluster while moving into the plane
of the sky at ~45 degrees. Off-axis mergers such as this one are an effective
mechanism for transferring angular momentum to the intracluster medium (ICM),
making possible a large scale rotation of the ICM. We demonstrate here that the
ICM rotation predicted by our fully 3-dimensional model of A3266 is observable
with current technology. As an example, we present simulated observations
assuming the capabilities of the high resolution X-ray spectrometer (XRS) which
was to have flown on Astro-E.Comment: 9 pages, 7 postscript figures, Fig. 3 and 6 are color postscript,
Accepted for publication in the Astrophysical Journa
ABJ(M) and Fractional M2's with Fractional M2 Charge
Recently Aharony, Bergman and Jafferis (ABJ) have argued that a 3d
U(N+M)xU(N) Chern-Simons gauge theory at level (k,-k) may have a vacuum with
N=6 supersymmetry only if M<k+1 and if a certain period of the B-field in a IIA
background is quantized. We use a braneology argument to argue that N=3
supersymmetry may be preserved under the weaker condition that 2Nk>M(M-k)-1
with no restriction on the B-field. IIB brane cartoons and 11d supergravity
solutions corresponding to N=3 vacua that do not preserve N=6 supersymmetry are
argued to represent cascading gauge theories, generalizing the N=2 Seiberg
duality conjectured by Giveon and Kutasov. While as usual the M2-brane charge
runs as a result of the twisted Bianchi identity for *G_4, the M5-brane charge
running relies on the fact that it wraps a torsion homology cycle.Comment: 16 pages, 3 eps figure
Embedding massive flavor in ABJM
We add massive fundamental matter to the ABJM model by adding D6-branes
wrapped asymptotically over RP3. We find two types of solutions at finite
temperature, one that enters the black hole and one that ends before the black
hole. We analyze the behavior of the free energy as a function of temperature,
and find that the system exhibits a phase transition between the two types of
solutions, similar to what happens in the D3-D7 system. We also analyze the
meson spectrum in the model and find several massive scalar modes, again, quite
like the D3-D7 system. We end with a calculation of the conductivities in the
two phases.Comment: 26 pages, 6 figures; version published in JHE
Can adenine nucleotides predict primary nonfunction of the human liver homograft?
Sixty-eight primary liver grafts were analyzed to see whether adenine nucleotides (AN: ATP, ADP, and AMP) or purine catabolites (PC: adenosine, inosine, hypoxanthine, and xanthine) of tissue or effluent can predict primary graft nonfunction. AN, PC, and nicotinamide adenine dinucleotide, oxidized form (NAD+) of the tissue before (pretransplant) and after graft reperfusion (post-transplant) and of the effluent were analyzed. The graft outcome was classified into two groups (group A: successful, n = 64; group B: primary nonfunctioning, n = 4). No significant differences were observed in pretransplant measurements between groups A and B, whereas ATP, ADP, total AN, total AN + total PC (T) and NAD+, in post-transplant tissues, were significantly higher in group A. Xanthine in the effluent was significantly higher in group B than in group A. ATP, ADP, total AN, T, and NAD+ in post-transplant tissue were significantly associated with primary graft nonfunction by logistic regression analysis
Metal-free syn-dioxygenation of alkenes
Reactions employing inexpensive reagents from sustainable sources and with low toxicity are becoming increasingly desirable from an academic and industrial perspective. A fascinating example of a synthetic transformation that requires development of alternative procedures is the osmium catalysed dihydroxylation. Recently there has been considerable interest in achieving this reaction through metal-free procedures. This review describes the methods available for metal-free syn-dioxygenation of alkenes
Time resolved magneto-optical spectroscopy on InGaAs nanostructures grown on (311)A and (100)-oriented substrates
We present a time-resolved magneto-photoluminescence study of In0.5Ga0.5As self-organized nanostructures grown on (100) and (311)A-oriented substrates by molecular beam epitaxy. The (311)A-oriented samples have a corrugated surface realizing a sort of quantum wire array, whereas the (100) samples exhibit Stranski–Krastanow islands. The different morphology of the nanostructures is reflected in the different electron/hole wave-function confinement along the three directions (perpendicular and parallel to the growth direction). We discuss the effects of the magnetic field (up to 8 T) on the recombination mechanism in these InGaAs nanostructures and on the transient dynamics of photoluminescence. We observe a clear decrease of the photoluminescence decay time with magnetic field flux indicating the exciton nature of the radiative low-temperature recombination processes
Page Curves for General Interacting Systems
We calculate in detail the Renyi entanglement entropies of cTPQ states as a
function of subsystem volume, filling the details of our prior work [Nature
Communications 9, 1635 (2018)], where the formulas were first presented.
Working in a limit of large total volume, we find universal formulas for the
Renyi entanglement entropies in a region where the subsystem volume is
comparable to that of the total system. The formulas are applicable to the
infinite temperature limit as well as general interacting systems. For example
we find that the second Renyi entropy of cTPQ states in terms of subsystem
volume is written universally up to two constants, , where is
the total volume of the system and and are two undetermined constants.
The uses of the formulas were already presented in our prior work and we mostly
concentrate on the theoretical aspect of the formulas themselves. Aside from
deriving the formulas for the Renyi Page curves, the expression for the von
Neumann Page curve is also derived, which was not presented in our previous
work.Comment: 29 pages, 3 figures; JHEP preparatio
Theory of superconductivity of carbon nanotubes and graphene
We present a new mechanism of carbon nanotube superconductivity that
originates from edge states which are specific to graphene. Using on-site and
boundary deformation potentials which do not cause bulk superconductivity, we
obtain an appreciable transition temperature for the edge state. As a
consequence, a metallic zigzag carbon nanotube having open boundaries can be
regarded as a natural superconductor/normal metal/superconductor junction
system, in which superconducting states are developed locally at both ends of
the nanotube and a normal metal exists in the middle. In this case, a signal of
the edge state superconductivity appears as the Josephson current which is
sensitive to the length of a nanotube and the position of the Fermi energy.
Such a dependence distinguishs edge state superconductivity from bulk
superconductivity.Comment: 5 pages, 2 figure
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