It is shown that there exists a range of parameters in which gravitational collapse with a spherically symmetric massive scalar field can be treated as if it were collapsing dust. This implies a criterion for the formation of black holes depending on the size and mass of the initial field configuration and the mass of the scalar field. Pacs numbers: 03.70.+k, 98.80.Cq Typeset using REVTEX

We discuss a new description for the Roper resonance, the first nucleon excited state of JP = 1/2+, in a model of strong diquark correlations. Treating the scalarisoscalar and axial-vector–isovector diquarks as independent degrees of freedom, two states having nucleon quantum numbers are constructed. Due to the scalar and axial-vector nature of the diquarks, the two nucleon states have differen...

We investigate the spectrum of physical states in the W 3 string theory, up to level 2 for a multi-scalar string, and up to level 4 for the two-scalar string. The (open) W 3 string has a photon as its only massless state. By using screening charges to study the null physical states in the two-scalar W 3 string, we are able to learn about the gauge symmetries of the states in the multi-scalar W ...

This paper describes an adaptive-grid nite-diierence solver for time-dependent three-dimensional systems of partial diierential equations. The robustness and the eeciency of the solver, both for vector and scalar processors, is illustrated by the application of the code to three example problems.

I propose a new theory of scalar implicatures: the speaker should be in the same epistemic status with respect to alternatives obtained via similar transformations (e.g., replacements of a scalar items with various stronger items). This theory extends naturally to explain presupposition projection. Cases where scalar items and presupposition triggers co-occur are also accounted for. The main fo...

Complexity arises from many sources – both within and outwith the system. Internal sources include modern hardware, e.g. super-scalar processors, and external sources include the requirements for evolving already successful systems. Complexity is inescapable – unless we are willing to reduce our dependence on computers, and to forgo the benefits they bring us. This raises the issue of how we co...

A generalization of the Yang-Mills covariant derivative, that uses both vector and scalar fields and transforms as a 4-vector contracted with Dirac matrices, is used to simplify the Glashow-Weinberg-Salam model. Since SU (3) assigns the wrong hypercharge to the Higgs boson, it is necessary to use a special representation of U (3) to obtain all the correct quantum numbers. A surplus gauge scalar...

We generalize to non-flat geometries the formalism of Simon et al. (2005) to reconstruct the dark energy potential. This formalismmakes use of quantities similar to the Horizon-flow parameters in inflation, can, in principle, be made non-parametric and is general enough to be applied outside the simple, single scalar field quintessence. Since presently available and forthcoming data do not allo...

The Kalman filtering method is extended to two dimensions. The resulting computational load is found to be excessive. Two new approximations are then introduced. One, called the strip processor, updates a line segment at a time; the other, called the reduced update Kalman filter, is a scalar processor. The reduced update Kalman filter is shown to be optimum in that it minimizes the post update ...

Several aspects of the design and optimization of coded multiple-antenna transmission diversity methods for slowly time-varying channels are explored from an information-theoretic perspective. Both optimized vector-coded systems, which can achieve the maximum possible performance, and suboptimal scalar-coded systems, which reduce complexity by exploiting suitably designed linear precoding, are ...