Near-flat space limit of strings on AdS 4×ℂℙ3

The non-linear nature of string theory on non-trivial backgrounds, related to the AdS/CFT correspondence, force one to look for simplifications. Two such simplifications proved to be useful in studying string theory. These are the pp-wave limit, which describes point-like strings, and the so-called “near-flat space” limit which connects two different sectors of string theory—pp-wave and “giant magnons”. Recently another example of AdS/CFT duality emerged—AdS ₄/CFT ₃, which suggests duality between CS theory and superstring theory on . In this paper we study the “near-flat space” limit of strings on an background and discuss possible applications of the limiting theory. R.C. Rashkov is on leave from Department of Physics, Sofia University, Bulgaria.     

Kristall- und Molekülstruktr von N,N′, N″- Trimethyl-N″- methylcarbamoylguanidiniumchlorid

N, N′, N″- Trimethyl-N″-Methyl-Carbamoylguanidinium Chloride The title compound is formed in small amounts by the chlorination of N, N′-dimethylurea with phosgene as a consecutive product, which crystallizes in the triclinic space group P1 with two formula units per cell. The cross-linkage of these two molecules with relative short N? H…?Cl…?H? N- bridges forming large, 16- membered ring systems is remarkable. The structure was refined to an R-value of 0.03.     

On the decay properties of 269Hs and indications for the new nuclide 270Hs

In bombardments of ²⁴⁸Cm with 143.7-146.8 MeV ²⁶Mg ions the nuclides ²⁶⁹Hs and presumably ²⁷⁰Hs were produced. After chemical isolation, Hs atoms were identified by observing genetically linked nuclear-decay chains. Three chains originating from ²⁶⁹Hs confirmed the decay properties observed previously in the decay of ²⁷⁷112. Two chains exhibited the characteristics expected for the new nuclide ²⁷⁰Hs, which was predicted to be a deformed doubly magic nucleus. From the measured MeV an -decay half-life of 3.6^+0.8_-1.4 s was estimated.Received: 18 July 2002, Revised: 3 April 2003, Published online: 22 July 2003PACS: 23.60.+e Alpha decay - 25.70.Gh Compound nucleus - 25.85.Ca Spontaneous fission - 27.90.+b