Results 21 to 30 of about 330 (59)

An easily verifiable proof of the Brouwer fixed point theorem [PDF]

open access: yes, 2011
We give a remarkably elementary proof of the Brouwer fixed point theorem.
Suzuki, Tomonari, Takeuchi, Yukio
core   +2 more sources

A Hadwiger Theorem for Simplicial Maps [PDF]

open access: yes, 2014
We define the notion of valuation on simplicial maps between geometric realizations of simplicial complexes in $\mathbb{R}^n$. Valuations on simplicial maps are analogous to valuations on sets.
Matthew L. Wright   +2 more
core  

Orbit spaces of free involutions on the product of two projective spaces

open access: yes, 2010
Let $X$ be a finitistic space having the mod 2 cohomology algebra of the product of two projective spaces. We study free involutions on $X$ and determine the possible mod 2 cohomology algebra of orbit space of any free involution, using the Leray ...
A. Borel   +18 more
core   +1 more source

The Lefschetz-Hopf theorem and axioms for the Lefschetz number

open access: yes, 2004
The reduced Lefschetz number, that is, the Lefschetz number minus 1, is proved to be the unique integer-valued function L on selfmaps of compact polyhedra which is constant on homotopy classes such that (1) L(fg) = L(gf), for f:X -->Y and g:Y -->X; (2 ...
Arkowitz, Martin, Brown, Robert F.
core   +4 more sources

Cohomology of preimages with local coefficients

open access: yes, 2006
Let M,N and B\subset N be compact smooth manifolds of dimensions n+k,n and \ell, respectively. Given a map f from M to N, we give homological conditions under which g^{-1}(B) has nontrivial cohomology (with local coefficients) for any map g homotopic to ...
Daccach   +10 more
core   +2 more sources

Parametrized Borsuk-Ulam problem for projective space bundles

open access: yes, 2010
Let $\pi: E \to B$ be a fiber bundle with fiber having the mod 2 cohomology algebra of a real or a complex projective space and let $\pi^{'}: E^{'} \to B$ be vector bundle such that $\mathbb{Z}_2$ acts fiber preserving and freely on $E$ and $E^{'}-0 ...
Singh, Mahender
core   +1 more source

Knaster's problem for $(Z_2)^k$-symmetric subsets of the sphere $S^{2^k-1}$

open access: yes, 2009
We prove a Knaster-type result for orbits of the group $(Z_2)^k$ in $S^{2^k-1}$, calculating the Euler class obstruction. Among the consequences are: a result about inscribing skew crosspolytopes in hypersurfaces in $\mathbb R^{2^k}$, and a result about ...
A. Borel   +28 more
core   +2 more sources

A Discrete Multivariate Mean Value Theorem with Applications [PDF]

open access: yes
AMS classifications: 47H10; 54H25; 55M20; 90C33; 91B50Discrete set;mean value theorem;fixed point;algorithm;equilibrium ...
Talman, A.J.J., Yang, Z.F.
core   +1 more source

Minimizing coincidence numbers of maps into projective spaces

open access: yes, 2008
In this paper we continue to study (`strong') Nielsen coincidence numbers (which were introduced recently for pairs of maps between manifolds of arbitrary dimensions) and the corresponding minimum numbers of coincidence points and pathcomponents.
Koschorke, Ulrich
core   +1 more source

A formula for the coincidence Reidemeister trace of selfmaps on bouquets of circles [PDF]

open access: yes, 2007
We give a formula for the coincidence Reidemeister trace of selfmaps on bouquets of circles in terms of the Fox calculus. Our formula reduces the problem of computing the coincidence Reidemeister trace to the problem of distinguishing doubly twisted ...
Staecker, P. Christopher
core   +4 more sources

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