Results 61 to 70 of about 4,197 (120)

On the curvatures of spacelike circular surfaces

Kuwait Journal of Science, 2016
In this paper a complete system of invariants is presented to study spacelike circular surfaces with fixed radius. Thestudy of spacelike circular surfaces is simplified to the study of two curves: the Lorentzian spherical indicatrix of theunit normals of
Rashad A. Abdel-Baky, Yasin Ünlütürk
doaj  

Singularities of multiplicative spherical Darboux image and multiplicative rectifying developable surface

Demonstratio Mathematica
In this study, singularity theory is used to explore the geometrical and topological properties of three types of curves and surfaces in multiplicative Euclidean space.
Li Jiaxin, Yao Xinyu, Ma Zikun, Liu Haiming   +3 more
doaj   +1 more source

On Asymptotic Series for Generalized Airy, Circular, and Hyperbolic Functions

Mathematics
The paper concerns the solution of the ordinary differential equation y″±xmy=0, which may be designated the generalized Airy equation, since the original Airy equation corresponds to the particular case m=1 with the + sign.
Luiz M. B. C. Campos, Manuel J. S. Silva
doaj   +1 more source

Transformation of caustic structures of the catastrophe type during the propagation of electromagnetic waves in cold plasma [PDF]

Известия высших учебных заведений: Прикладная нелинейная динамика
The purpose of the work is to investigate the possibilities of formation of centers of topological caustic singularities of the catastrophe type during probing of a unimodal plasma layer by electromagnetic waves.
Kryukovsky, Andrey Sergeevich, Rastyagaev, Dmitry Vladimirovich   +1 more
doaj   +1 more source

Algorithms in SINGULAR

Comput. Sci. J. Moldova, 1996
The author shows how to use SINGULAR to solve some problems of algebraic geometry. SINGULAR is a computer algebra system whose basic algorithms are variants of a general standard basis algorithm for general monomial orderings. There are several examples in the paper.
openaire   +4 more sources

ГРУППЫ СИММЕТРИЙ УРАВНЕНИЙ ПЕНЛЕВЕ

Vestnik KRAUNC: Fiziko-Matematičeskie Nauki, 2012
В данной работе для 50 нелинейных ОДУ второго порядка, обладающих свойством Пенлеве, найдены однопараметрические группы симметрий и в некоторых случаях построены обшие решения.
Noshchenko, D.S., Ilyin, I.A.
doaj   +1 more source

Painleve's determinateness theorem extended to proper coverings

Electronic Journal of Differential Equations, 2010
We extend Painleve's determinateness theorem to first-order ordinary differential equations in the complex domain, with known terms allowed be multivalued in the dependent variable. The multivaluedness is supposed to be resolved by proper coverings.
Claudi Meneghin
doaj  

Symplectic U7,U8 and U9 Singularities

Demonstratio Mathematica, 2015
We use the method of algebraic restrictions to classify symplectic U7, U8 and U9 singularities. We use discrete symplectic invariants to distinguish symplectic singularities of the curves.
Trębska Żaneta
doaj   +1 more source

□ on the singular cardinals

Journal of Symbolic Logic, 2008
AbstractWe give upper and lower bounds for the consistency strength of the failure of a combinatorial principle introduced by Jensen. Square on singular cardinals.
James Cummings 0001, Sy-David Friedman
openaire   +2 more sources

Singularity categories and singular loci of certain quotient singularities

Let $V$ be a finite dimensional $k$-vector space, where $k$ is an algebraic closed field of characteristic zero. Let $G \subseteq \mathrm{SL}(V)$ be a finite abelian group, and denote by $S$ the $G$-invariant subring of the polynomial ring $k[V]$. It is shown that the singularity category $D_{sg}(S)$ recovers the reduced singular locus of $\mathrm{Spec}
Chen, Xiaojun, Zeng, Jieheng
openaire   +2 more sources