Research ArticleOpen accessPhrase in the titleDeformation Retracts of the Reissner-Nordstrom Spacetime and its FoldingsA. E. El-Ahmady, A. Al-RdadeOur aim in the present article is to introduce and study the relation between the deformation retract of the Reissner-Nordstrom spacetime N4 and the deformation retract of the tangent space Tp (N4). Also, this relation discussed after and before the isometric and topological folding of N4 into itself. New types of conditional folding are presented. Some commutative diagrams are obtained. …American Journal of Applied Sciences, Vol. 10, Issue 7 · 2 Jul 2013 · 6,447 accessesView PDFCite
Research ArticleOpen accessIn the keywordsFoldings and Deformation Retract of HyperhelixE. AL-Hesiny, A. E. El-AhmadyOur aim in the present study is to introduce and study new types of retractions of hyperhelix in Minkowski space. Types of the deformation retracts of hyperhelix in Minkowski space were discussed. The relations between the foldings and the deformation retracts of hyperhelix in Minkowski space were deduced. Types of minimal retractions of hyperhelix in Minkowski space were obtained. Also, … …Journal of Mathematics and Statistics, Vol. 8, Issue 2 · 5 Jun 2012 · 7,119 accessesView PDFCite