A bstract We analyze the BPS equations in “superstratum sector” of three-dimensional gauged supergravity. obtain multi-parameter supersymmetric solutions that include elliptical deformations supertubes underlie standard superstrata. uplift to corresponding six-dimensional geometries. This yields new families elliptically-deformed, ambi-bolar hyper-Kähler geometries four dimensions with a non-tr...

Some aspects of integrable field theories possessing purely transmitting defects are described. The main example is the sine-Gordon model and several striking features of a classical field theory containing one or more defects are pointed out. Similar features appearing in the associated quantum field theory are also reviewed briefly. 1 Classical picture The context of this topic is two-dimensi...

This paper describes a purely functional dialect of the algorithmic programming language Scheme. Mutable variables, assignment operations and impure control operations (call-with-current-continuation) have been omitted, while side effecting input and output operations are incorporated into the purely functional language using monads, similar to the approach taken in the lazy programming languag...

Spacetimes in which the electric part of the Weyl tensor vanishes (relative to some timelike unit vector field) are said to be purely magnetic. Examples of purely magnetic spacetimes are known and are relatively easy to construct, if no restrictions are placed on the energy-momentum tensor. However it has long been conjectured that purely magnetic vacuum spacetimes (with or without a cosmologic...

We report on a compilation procedure that derives relational algebra plans from arbitrarily nested XQuery FLWOR blocks. While recent research was able to develop relational encodings of trees which may turn RDBMSs into highly efficient XPath and XML Schema processors, here we describe relational encodings of nested iteration, variables, and the item sequences to which variables are bound. The d...

Many applications have to maintain evolving data sources as well as views on these sources. If sources change, the corresponding views have to be adapted. Complete recomputation of views is typically too expensive. An alternative is to convert source changes into view changes and apply these to the views. This is the key idea of incremental computing. In this paper, we use Haskell to develop an...

An efficient and convenient protocol for synthesis of 3-hydroxy-3-indolyl-2-oxindoles and 3,3-diindolyl-2-oxindoles is presented here. The syntheses were achieved selectively under catalysis of LiClO4 whereby the products were obtained purely.