13,887 research outputs found
Type IIA Orientifold Limit of M-Theory on Compact Joyce 8-Manifold of Spin(7)-Holonomy
We show that M-theory compactified on a compact Joyce 8-manifold of
-holonomy, which yields an effective theory in with = 1
supersymmetry, admits at some special points in it moduli space a description
in terms of type IIA theory on an orientifold of compact Joyce 7-manifold of
-holonomy. We find the evidence in favour of this duality by computing the
massless spectra on both M-thory side and type IIA side. For the latter, we
compute the massless spectra by going to the orbifold limit of the Joyce
7-manifold.Comment: 26 pages, 2 eps figures, Latex file, two references and one footnote
added, corrected some typo
Measurement of the iron spectrum from 60 to 200 GeV per nucleon
The high energy gas Cerenkov Spectrometer (HEGCS) was flown by balloon from Palestine, Texas on September 30, 1983. The instrument maintained an altitude of 118,000 ft (4.7 g/sq cms) for 6 hours. Details of the ongoing data analysis and preliminary results on the Fe spectrum to 10 to the 13th power eV/nucleus are given
Liouville soliton surfaces obtained using Darboux transformations
We construct parametric Liouville surfaces corresponding to parametric soliton solutions of the Liouville equation and Darboux-transformed counterparts. We also use a modified variation of parameters method together with the elliptic functions method to obtain the traveling wave solutions to Liouville equation and express the centroaffine invariant in terms of the soliton Hamiltonian
Primary sclerosing cholangitis in India
Six patients with PSC have been diagnosed and followed up at a centre in Northern India for periods upto 4 years. They all presented with cholestatic jaundice and cholangitis, but one of them subsequently presented with variceal haemorrhage. Cholangiographic features were the most characteristic and included irregular narrowing and segmental dilatation of the biliary radicles giving them a beaded appearance. Treating them was most frustrating. Two of them died of hepatic encephalopathy, others have also continued to be sick during the follow-up
Broadband study of blazar 1ES 1959+650 during flaring state in 2016
Aim : The nearby TeV blazar 1ES 1959+650 (z=0.047) was reported to be in
flaring state during June - July 2016 by Fermi-LAT, FACT, MAGIC and VERITAS
collaborations. We studied the spectral energy distributions (SEDs) in
different states of the flare during MJD 57530 - 57589 using simultaneous
multiwaveband data to understand the possible broadband emission scenario
during the flare. Methods : The UV/optical and X-ray data from UVOT and XRT
respectively on board Swift and high energy -ray data from Fermi-LAT
are used to generate multiwaveband lightcurves as well as to obtain high flux
states and quiescent state SEDs. The correlation and lag between different
energy bands is quantified using discrete correlation function. The synchrotron
self Compton (SSC) model was used to reproduce the observed SEDs during flaring
and quiescent states of the source. Results : A decent correlation is seen
between X-ray and high energy -ray fluxes. The spectral hardening with
increase in the flux is seen in X-ray band. The powerlaw index vs flux plot in
-ray band indicates the different emission regions for 0.1 - 3 GeV and
3-300 GeV energy photons. Two zone SSC model satisfactorily fits the observed
broadband SEDs. The inner zone is mainly responsible for producing synchrotron
peak and high energy -ray part of the SED in all states. The second
zone is mainly required to produce less variable optical/UV and low energy
-ray emission. Conclusions : Conventional single zone SSC model does
not satisfactorily explain broadband emission during observation period
considered. There is an indication of two emission zones in the jet which are
responsible for producing broadband emission from optical to high energy
-rays.Comment: 11 pages, 12 figures, Accepted in A&
Kahler Independence of the G2-MSSM
The G2-MSSM is a model of particle physics coupled to moduli fields with
interesting phenomenology both for colliders and astrophysical experiments. In
this paper we consider a more general model - whose moduli Kahler potential is
a completely arbitrary G2-holonomy Kahler potential and whose matter Kahler
potential is also more general. We prove that the vacuum structure and spectrum
of BSM particles is largely unchanged in this much more general class of
theories. In particular, gaugino masses are still supressed relative to the
gravitino mass and moduli masses. We also consider the effects of higher order
corrections to the matter Kahler potential and find a connection between the
nature of the LSP and flavor effects.Comment: Final version, matches the version published in JHE
Affleck-Dine baryogenesis in inflating curvaton scenario with O(TeV) mass moduli curvaton
We study the Affleck-Dine (AD) baryogenesis in the inflating curvaton
scenario, when the curvaton is a moduli field with O(TeV) mass. A
moduli field with such mass is known to be free from the Polonyi problem, and
furthermore its decay products can explain the present cold dark matter
abundance. In our scenario, it further explains the primordial curvature
perturbation and the present baryon density all together. The current
observational bound on the baryon isocurvature perturbation, which severely
constrains the AD baryogenesis with the original oscillating moduli curvaton
scenario, is shown to put practically negligible constraint if we replace the
oscillating curvaton with the inflating curvaton.Comment: 1+21pages v2: minor correction v3: included short reviews, added
refs, fixed typo
Towards A Topological G_2 String
We define new topological theories related to sigma models whose target space
is a 7 dimensional manifold of G_2 holonomy. We show how to define the
topological twist and identify the BRST operator and the physical states.
Correlation functions at genus zero are computed and related to Hitchin's
topological action for three-forms. We conjecture that one can extend this
definition to all genus and construct a seven-dimensional topological string
theory. In contrast to the four-dimensional case, it does not seem to compute
terms in the low-energy effective action in three dimensions.Comment: 15 pages, To appear in the proceedings of Cargese 2004 summer schoo
Chronic calcific pancreatitis: clinical profile in northern India
Twenty three patients with chronic calcific pancreatitis of the tropics in Northern India were prospectively studied. All had pancreatic calcification and ERCP changes typical of chronic pancreatitis, the most predominant being ductal dilatation which was detected in all patients by both ERCP and by ultrasonography. Pain was present in 19 (83%) patients and diabetes in 11 (48%) patients. Exocrine pancreatic dysfunction was uncommon, steatorrhoea being present in only 9% of patients. Ten of the 11 patients with diabetes required insulin for control and one case was able to be controlled by an oral antidiabetic agent. Two patients developed ketoacidosis during acute episodes of pancreatitis, 3 patients had peripheral neuropathy and one patient had visual changes. Recurrent severe pain was the reason for operation in 7 patients. All had a lateral pancreaticojejunostomy. In order to obtain an objective assessment of pain, a scoring system was developed to grade its severity according to its intensity, frequency and consequences. Six patients who preoperatively had a pain score of 15 or more (out of a maximum score of 24) attained significant relief after the surgery. We feel this scoring system may provide an easy objective assessment of pain in the subsequent follow-up of these patients
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