F-string solution in AdS4 ×𝒞𝒫3 pp-wave background

We present supergravity solution for F-string in pp-wave background obtained from [Formula: see text] with zero flat direction. The classical solution is shown to break all space–time supersymmetries. We explicitly write down the standard as well as supernumerary Killing spinors both for the background and F-string solution.

Regular Bulk Solutions in Brane-Worlds with Inhomogeneous Dust and Generalized Dark Radiation

From the dynamics of a brane-world with matter fields present in the bulk, the bulk metric and the black string solution near the brane are generalized, when both the dynamics of inhomogeneous dust/generalized dark radiation on the brane-world and inhomogeneous dark radiation in the bulk as well are considered as exact dynamical collapse solutions. Based on the analysis on the inhomogeneous static exterior of a collapsing sphere of homogeneous dark radiation on the brane, the associated black string warped horizon is studied, as well as the 5D bulk metric near the brane. Moreover, the black string and the bulk are shown to be more regular upon time evolution, for suitable values for the dark radiation parameter in the model, by analyzing the soft physical singularities.

GENERALIZED LIE TRANSPORTED STRING IN T-FOLD WITH GENERALIZED KILLING VECTOR

After constructing the [Formula: see text]-brane background, which is a T-fold in string theory, from a D7-brane via U-duality, we derived the fundamental string solution rotating around it. Reflecting that the [Formula: see text] background is not axisymmetric, the string solution also changes its shape during its rotation. However, we found that the [Formula: see text] background is indeed axisymmetric in the sense of doubled geometry, by explicitly finding a generalized Killing vector. Moreover, the string charge density vector is found to be generalized Lie transported along the generalized Killing vector.

HYPERCYLINDRICAL VACUUM SPACETIME SOLUTIONS

A brief report is given on hypercylindrical vacuum spacetime solutions and their geometrical properties. The five-dimensional Schwarzschild black string solution characterized by the mass density, which is known to reveal the so-called Gregory-Laflamme instability, turns out to be a special case of a wider class of hypercylindrical vacuum spacetime solutions characterized by two parameters, i.e., mass density and tension. Recent work on the solution space even including a momentum flow or a cosmological constant, higher dimensional extensions than five and some stability analysis under small perturbations are briefly summarized.

ASYMPTOTIC TRANSITION FROM COSSERAT ROD TO STRING MODELS FOR CURVED VISCOUS INERTIAL JETS

This work deals with the modeling and simulation of slender viscous jets exposed to gravity and rotation, as they occur in rotational spinning processes. In terms of slender-body theory, we show the asymptotic reduction of a viscous Cosserat rod to a string system for vanishing slenderness parameter. We propose two string models, i.e. inertial and viscous-inertial string models, that differ in the closure conditions and hence yield a boundary value problem and an interface problem, respectively. We investigate the existence regimes of the string models in the four-parametric space of Froude, Rossby, Reynolds numbers and jet length. The convergence regimes where the respective string solution is the asymptotic limit to the rod turn out to be disjoint and to cover nearly the whole parameter space. We explore the transition hyperplane and derive analytically low and high Reynolds number limits. Numerical studies of the stationary jet behavior for different parameter ranges complete the work.

Integrated Surveillance Enhancing Quality of Decisions and Reservoir Description in the Harding Field

Summary A key factor in managing mature fields is to establish adequate surveillance in each phase of their life. The complexity increases when the field is developed with horizontal wells. Differences in data quality and resolution should be taken into consideration when planning such surveillance. Current uncertainties in Harding field relate to unreliable well conformance data using conventional production logs (PL) and assumptions in the reservoir description, which are subseismic resolution. We describe the learning from a horizontal well in Harding, where appropriate surveillance enhanced reservoir understanding and quality of decision making. Based on the initial understanding from the reservoir model, an insert string well work option was proposed to reduce water cut. Historically in this field, conventional PLs provided unreliable well conformance data in horizontal multiphase flow. To improve the characterization at the well scale, an array PL was deployed for the first time on this field. The flowing results revealed that the insert string solution was inappropriate and would result in lost oil production. The shut-in data identified crossflow between two zones separated by a shale section. In the initial model, this shale was mapped only at local level. Post surveillance, it was remapped on seismic as an extensive baffle having an impact on an area with more mobile oil to recover. There is a potential upside with a new infill target being identified toward the toe of this well. Most of the initial decisions about the insert string were based on seismic and modeling work. The new array PL data brought additional information into the model, increasing confidence in the results. Data resolution at the well level matters and this highlights the need to take more PL measurements to calibrate the seismic response and improve the reservoir model.

ASYMPTOTIC AdS STRING SOLUTIONS FOR NULL POLYGONAL WILSON LOOPS IN R1,2

For the asymptotic string solution in AdS3 which is represented by the AdS3 Poincaré coordinates and yields the planar multi-gluon scattering amplitude at strong coupling in arXiv:0904.0663, we express it by the AdS4 Poincaré coordinates and demonstrate that the hexagonal and octagonal Wilson loops surrounding the string surfaces take closed contours consisting of null vectors in R1,2 owing to the relations of Stokes matrices. For the tetragonal Wilson loop we construct a string solution characterized by two parameters by solving the auxiliary linear problems and demanding a reality condition, and analyze the asymptotic behavior of the solution in R1,2. The freedoms of two parameters are related with some conformal SO(2,4) transformations.

STABILITY OF GLOBAL VERTEX SOLUTION IN HIGHER-DIMENSIONAL SPACETIME

It is well known that higher-dimensional black objects with translational invariance are unstable, which is called Gregory-Laflamme instability. There is a question if this instability is eliminated by adding a scalar hair to the black objects. For the first step, we investigate a regular topological string solution and its stability in the five-dimensional Einstein-Higgs system. Linear analysis shows that the string solution is stable against non-uniform perturbations.