# Rétractes Absolus de Voisinage Algébriques

Serdica Mathematical Journal (2005)

- Volume: 31, Issue: 4, page 309-354
- ISSN: 1310-6600

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topCauty, Robert. "Rétractes Absolus de Voisinage Algébriques." Serdica Mathematical Journal 31.4 (2005): 309-354. <http://eudml.org/doc/219661>.

@article{Cauty2005,

abstract = {2000 Mathematics Subject Classification: 54C55, 54H25, 55M20.We introduce the class of algebraic ANRs. It is defined by
replacing continuous maps by chain mappings in Lefschetz’s characterization of ANRs. To a large extent, the theory of algebraic ANRs parallels the classical theory of ANRs. Every ANR is an algebraic ANR, but the class of algebraic ANRs is much larger; the most striking difference between these classes is that every locally equiconnected metrisable space is an algebraic
ANR, whereas there exist metric linear spaces which are not ARs. This is important for applications of topological fixed point theory to functional analysis because all known results of fixed point for compact maps of ANRs
extend to the algebraic ANRs. We prove here two such generalizations: the
Lefschetz-Hopf fixed point theorem for compact maps of algebraic ANRs,
and the fixed point theorem for compact upper semi-continuous multivalued maps with Q-acyclic compacts point images in a Q-acyclic algebraic ANR. We stress that these generalizations apply to all neighborhood retract of a metrisable linear space and, more generally, of a locally contractible metrisable group.},

author = {Cauty, Robert},

journal = {Serdica Mathematical Journal},

keywords = {Algebraic ANRs; Lefschetz-Hopf Fixed Point Theorem; Lefschetz-Hopf fixed point theorem},

language = {fre},

number = {4},

pages = {309-354},

publisher = {Institute of Mathematics and Informatics Bulgarian Academy of Sciences},

title = {Rétractes Absolus de Voisinage Algébriques},

url = {http://eudml.org/doc/219661},

volume = {31},

year = {2005},

}

TY - JOUR

AU - Cauty, Robert

TI - Rétractes Absolus de Voisinage Algébriques

JO - Serdica Mathematical Journal

PY - 2005

PB - Institute of Mathematics and Informatics Bulgarian Academy of Sciences

VL - 31

IS - 4

SP - 309

EP - 354

AB - 2000 Mathematics Subject Classification: 54C55, 54H25, 55M20.We introduce the class of algebraic ANRs. It is defined by
replacing continuous maps by chain mappings in Lefschetz’s characterization of ANRs. To a large extent, the theory of algebraic ANRs parallels the classical theory of ANRs. Every ANR is an algebraic ANR, but the class of algebraic ANRs is much larger; the most striking difference between these classes is that every locally equiconnected metrisable space is an algebraic
ANR, whereas there exist metric linear spaces which are not ARs. This is important for applications of topological fixed point theory to functional analysis because all known results of fixed point for compact maps of ANRs
extend to the algebraic ANRs. We prove here two such generalizations: the
Lefschetz-Hopf fixed point theorem for compact maps of algebraic ANRs,
and the fixed point theorem for compact upper semi-continuous multivalued maps with Q-acyclic compacts point images in a Q-acyclic algebraic ANR. We stress that these generalizations apply to all neighborhood retract of a metrisable linear space and, more generally, of a locally contractible metrisable group.

LA - fre

KW - Algebraic ANRs; Lefschetz-Hopf Fixed Point Theorem; Lefschetz-Hopf fixed point theorem

UR - http://eudml.org/doc/219661

ER -

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