Search results for "General Mathematics"

Multiplicity of Boardman strata and deformations of map germs

1998

AbstractWe define algebraically for each map germ f:Kn,0→Kp, 0 and for each Boardman symbol i=(i1,…,ik) a number ci(f) which is -invariant. If f is finitely determined, this number is the generalization of the Milnor number of f when p = 1, the number of cusps of f when n = p = 2, or the number of cross caps when n = 2, p = 3. We study some properties of this number and prove that, in some particular cases, this number can be interpreted geometrically as the number of Σi points that appear in a generic deformation of f. In the last part, we compute this number in the case that the map germ is a projection and give some applications to catastrophe map germs.

On CM points away from the Torelli locus

2021

Dichte Klassen konvexer Polytope

1978

Eine Verallgemeinerung eines Satzes von N. Kuiper

1976

Zweifach transitive Permutationsgruppen, in denen 2 die maximale Anzahl von Fixpunkten von Involutionen ist

1968

Ein Kriterium f�r Quasik�rperA(F, ?, (g i ), (f i ),n)

1991

Weights, vertices and a correspondence of characters in groups of odd order

1993

Products of groups with finite rank

1987

Group algebras whose units satisfy a group identity

1997

Let F G FG be the group algebra of a torsion group over an infinite field F F . Let U U be the group of units of F G FG . We prove that if U U satisfies a group identity, then F G FG satisfies a polynomial identity. This confirms a conjecture of Brian Hartley.

Permutability in finite soluble groups

1994

Let G be a finite soluble group and let Σ be a Hall system of G. A subgroup U of G is said to be Σ-permutable if U permutes with every member of Σ. In [1; I, 4·29] it is proved that if U and V are Σ-permutable subgroups of G then so also are U ∩ V and 〈U, V〉.