Sandwich type theorems
Seiberg-Witten invariants, the topological degree and wall crossing formula
Following S. Bauer and M. Furuta we investigate finite dimensional approximations of a monopole map in the case b 1 = 0. We define a certain topological degree which is exactly equal to the Seiberg-Witten invariant. Using homotopy invariance of the topological degree a simple proof of the wall crossing formula is derived.
Selections and near-selections in metric linear spaces without local convexity
We characterize the AR property in convex subsets of metric linear spaces in terms of certain near-selections.
Sequences of fixed point indices of iterations in dimension 2.
Smith equivalence and finite Oliver groups with Laitinen number 0 or 1.
Smith theory and quasi-periodicity in Bredon cohomology
Smith theory and the functor T.
Smith theory for algebraic varieties.
Solvability Of Operator Equations And Periodic Solutions Of Semilinear Hyperbolic Equations
Solving Systems of Polynomial Equations by Bounded and Real Homotopy.
Some applications of Coincidence theory.
Some applications of the topological degree theory to multi-valued boundary value problems [Book]
Some combinatorial results about the operators with jumping nonlinearities
Some elementary applications of topological degree.
Some extension and classification theorems for maps of movable spaces
Some homotopy theoretical questions arising in Nielsen coincidence theory
Basic examples show that coincidence theory is intimately related to central subjects of differential topology and homotopy theory such as Kervaire invariants and divisibility properties of Whitehead products and of Hopf invariants. We recall some recent results and ask a few questions which seem to be important for a more comprehensive understanding.
Some new results on composition of quadratic forms.
Some Results on Maps That Factor through a Tree
We give a necessary and sufficient condition for a map deffned on a simply-connected quasi-convex metric space to factor through a tree. In case the target is the Euclidean plane and the map is Hölder continuous with exponent bigger than 1/2, such maps can be characterized by the vanishing of some integrals over winding number functions. This in particular shows that if the target is the Heisenberg group equipped with the Carnot-Carathéodory metric and the Hölder exponent of the map is bigger than...
Spaces with fibered approximation property in dimension n
A metric space M is said to have the fibered approximation property in dimension n (briefly, M ∈ FAP(n)) if for any ɛ > 0, m ≥ 0 and any map g: m × n → M there exists a map g′: m × n → M such that g′ is ɛ-homotopic to g and dim g′ (z × n) ≤ n for all z ∈ m. The class of spaces having the FAP(n)-property is investigated in this paper. The main theorems are applied to obtain generalizations of some results due to Uspenskij [11] and Tuncali-Valov [10].
Spherical maps