منابع مشابه
Symmetric symplectic homotopy K3 surfaces
A study on the relation between the smooth structure of a symplectic homotopy K3 surface and its symplectic symmetries is initiated. A measurement of exoticness of a symplectic homotopy K3 surface is introduced, and the influence of an effective action of a K3 group via symplectic symmetries is investigated. It is shown that an effective action by various maximal symplectic K3 groups forces the...
متن کاملHomotopy in non metrizable ω-bounded surfaces
We investigate the problem of describing the homotopy classes [X,Y ] of continuous functions between ω-bounded non metrizable manifolds X,Y . We define a family of surfaces X built with the first octant C in L (L is the longline and R the longray), and show that [X,R] is in bijection with so called ‘adapted’ subsets of a partially ordered set. We also show that [M,R] can be computed for some su...
متن کاملProjections of Immersed Surfaces and Regular Homotopy
This thesis is based on U. Pinkall’s study of the classification of immersions of compact surfaces into R3 up to regular homotopy. The main idea of the classification is to associate to any immersion f a quadratic form qf on the first homology group of the underlying surface Σ with Z2 coefficients, whose associated bilinear form is the nondegenerate intersection form in H1(Σ,Z2), having the pro...
متن کاملRegular Homotopy Classes of Immersed Surfaces
IN this paper we are concerned with the problem of classifying compact surfaces immersed in Iw” up to regular homotopyt. This subject started in 1958 when Smale classified the immersions of the 2-sphere [17]. For n 2 4 the problem was then completely solved by Hirsch ([8], theorems 8.2 and 8.4): if M2 is a compact surface then for n 2 5 any two immersions f, g : M2 + R” are regularly homotopic,...
متن کاملOn 2-Dimensional Homotopy Invariants of Complements of Knotted Surfaces
We prove that ifM is a compact 4-manifold provided with a handle decomposition with 1-skeleton X , and if G is a finite crossed module, then the number of crossed module morphisms from the fundamental crossed module Π2(M,X , ∗) = (π1(X , ∗), π2(M,X , ∗), ∂, ⊲) into G can be re-scaled to a manifold invariant IG (i. e. not dependent on the choice of 1-skeleton), a construction similar to David Ye...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Topology
سال: 1975
ISSN: 0040-9383
DOI: 10.1016/0040-9383(75)90031-2