Title of article :
Geometric formulas for Smale invariants of codimension two immersions
Author/Authors :
Ekholm، نويسنده , , Tobias and Szücs، نويسنده , , Andrلs، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2003
Abstract :
We give three formulas expressing the Smale invariant of an immersion f of a (4k−1)-sphere into (4k+1)-space. The terms of the formulas are geometric characteristics of any generic smooth map g of any oriented 4k-dimensional manifold, where g restricted to the boundary is an immersion regularly homotopic to f in (6k−1)-space.
rmulas imply that if f and g are two non-regularly homotopic immersions of a (4k−1)-sphere into (4k+1)-space then they are also non-regularly homotopic as immersions into (6k−1)-space. Moreover, any generic homotopy in (6k−1)-space connecting f to g must have at least ak(2k−1)! cusps, where ak=2 if k is odd and ak=1 if k is even.
Keywords :
Euler Number , Smale invariant , Pontryagin number , IMMERSION , Cusp , Singularity , Linking