4,440 research outputs found
Multi-dimensional modelling of spray, in-cylinder air motion and fuel-air mixing in a direct-injection engine
Schwinger-Keldysh Propagators from AdS/CFT Correspondence
We demonstrate how to compute real-time Green's functions for a class of
finite temperature field theories from their AdS gravity duals. In particular,
we reproduce the two-by-two Schwinger-Keldysh matrix propagator from a gravity
calculation. Our methods should work also for computing higher point Lorentzian
signature correlators. We elucidate the boundary condition subtleties which
hampered previous efforts to build a Lorentzian-signature AdS/CFT
correspondence. For two-point correlators, our construction is automatically
equivalent to the previously formulated prescription for the retarded
propagator.Comment: 16 pages, 1 figure, references added; to appear in JHE
A new diagrammatic representation for correlation functions in the in-in formalism
In this paper we provide an alternative method to compute correlation
functions in the in-in formalism, with a modified set of Feynman rules to
compute loop corrections. The diagrammatic expansion is based on an iterative
solution of the equation of motion for the quantum operators with only retarded
propagators, which makes each diagram intrinsically local (whereas in the
standard case locality is the result of several cancellations) and endowed with
a straightforward physical interpretation. While the final result is strictly
equivalent, as a bonus the formulation presented here also contains less graphs
than other diagrammatic approaches to in-in correlation functions. Our method
is particularly suitable for applications to cosmology.Comment: 14 pages, matches the published version. includes a modified version
of axodraw.sty that works with the Revtex4 clas
Effect of Organic Manures and Biofertilizers on Leaf and Fruit Nutrient Status in Guava (Psidium guajava L.) Cv. Sardar
Pooled analysis of two-year data on nutrient status of 'Sardar' guava raised under organic manures and biofertilizers indicated that maximum leaf nitrogen (1.73%), phosphorus (0.24%), potassium (1.23%), calcium (1.96%), magnesium (0.80%); and maximum fruit nitrogen (1.12%), phosphorus (0.15%), potassium (0.94%), calcium (0.22%), magnesium (0.66%) was recorded, respectively, after fruit harvest with application of full dose of nitrogen to the plant applied through poultry manure augmented with Azotobacter and Azospirillium
Parallel algorithm with spectral convergence for nonlinear integro-differential equations
We discuss a numerical algorithm for solving nonlinear integro-differential
equations, and illustrate our findings for the particular case of Volterra type
equations. The algorithm combines a perturbation approach meant to render a
linearized version of the problem and a spectral method where unknown functions
are expanded in terms of Chebyshev polynomials (El-gendi's method). This
approach is shown to be suitable for the calculation of two-point Green
functions required in next to leading order studies of time-dependent quantum
field theory.Comment: 15 pages, 9 figure
Validation of Postnatal Care Health Data Reported Under Health Management Information System by the Primary Health Centers of Rural Vadodara, Gujarat
Postnatal care (PNC) is a part of maternal and child health (MCH) and important for the good health of both motherand child. Therefore, the present study was conducted with the aim to study the PNC data reported by primary health center/subcenter (PHC/SC) and validate them at the village level and assess quality of care given. Material and methods: A sampleof 20 PHCs, 13 rural and seven tribal, was selected using stratified random sampling. For every PHC, 2 SCs and for every SC,one village were selected. Data on PNC were collected from the PHC/SC records and validated by interviewing five beneficiariesfrom the village. Results: The district availability of PNC was 31.8%, while the overall accessibility was 52.2%. Adjustedutilization for the district was 74.7% for SBA and 14.7% for TBA. Effective coverage, adjusted for quality of care, for the districtwas 25.2%. Conclusions: The gap between the reported and validated data ranged from 15% to 51% of the reported
Holographic Construction of Excited CFT States
We present a systematic construction of bulk solutions that are dual to CFT
excited states. The bulk solution is constructed perturbatively in bulk fields.
The linearised solution is universal and depends only on the conformal
dimension of the primary operator that is associated with the state via the
operator-state correspondence, while higher order terms depend on detailed
properties of the operator, such as its OPE with itself and generally involve
many bulk fields. We illustrate the discussion with the holographic
construction of the universal part of the solution for states of two
dimensional CFTs, either on or on . We compute the
1-point function both in the CFT and in the bulk, finding exact agreement. We
comment on the relation with other reconstruction approaches.Comment: 26 pages, 4 figures, v2: comments adde
PIN21 Age Related Consultation Rates of Clinically-Diagnosed Influenza And Acute Respiratory Illnesses Observed Through A Network of Gp Practices Across England
Renormalization of initial conditions and the trans-Planckian problem of inflation
Understanding how a field theory propagates the information contained in a
given initial state is essential for quantifying the sensitivity of the cosmic
microwave background to physics above the Hubble scale during inflation. Here
we examine the renormalization of a scalar theory with nontrivial initial
conditions in the simpler setting of flat space. The renormalization of the
bulk theory proceeds exactly as for the standard vacuum state. However, the
short distance features of the initial conditions can introduce new divergences
which are confined to the surface on which the initial conditions are imposed.
We show how the addition of boundary counterterms removes these divergences and
induces a renormalization group flow in the space of initial conditions.Comment: 22 pages, 4 eps figures, uses RevTe
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