# Erratum to "Fixed Points of Maps of a Nonaspherical Wedge"

- Seungwon Kim
^{1}, - RobertF Brown
^{2}Email author, - Adam Ericksen
^{3}, - Nirattaya Khamsemanan
^{4}and - Keith Merrill
^{5}

**2010**:820265

**DOI: **10.1155/2010/820265

© Seungwon Kim et al. 2010

**Received: **21 June 2010

**Accepted: **17 July 2010

**Published: **8 August 2010

## Abstract

In the original paper, it was assumed that a selfmap of , the wedge of a real projective space and a circle , is homotopic to a map that takes to itself. An example is presented of a selfmap of that fails to have this property. However, all the results of the paper are correct for maps of the pair .

Let
be the wedge of the real projective plane
and the circle
. As the example below demonstrates, the statement on page 3 of [1] "Given a map
we may deform
by a homotopy so that
, its restriction to
, maps
to itself." is incorrect. If, instead of an arbitrary self-map of
, we consider a map of pairs
, the map can be put in the *standard form* defined on that page and then all the results of the paper are correct for such maps of pairs.

We complete the definition of by setting for . Note that such that . We may embed in the universal covering space because is an infinite tree with a 2-sphere replacing each vertex in such a way that two edges are attached at each of two antipodal points. The embedding induces a monomorphism of homology. The map has been defined so that if are antipodal points of , then and therefore induces a map . If were homotopic to a map , then the homotopy would lift to cover by a map which sends to a single -sphere in . Therefore the image of would be either trivial or a single generator of . On the other hand, the image of in is nontrivial for three generators, so no such homotopy can exist. Therefore, if is a map whose restriction to is the map defined above, then it cannot be homotoped to a map that takes to itself.

## Notes

## Declarations

### Acknowledgment

The authors thank Francis Bonahon and Geoffrey Mess for their help with the example.

## Authors’ Affiliations

## References

- Kim SW, Brown RF, Ericksen A, Khamsemanan N, Merrill K:
**Fixed points of maps of a nonaspherical wedge.***Fixed Point Theory and Applications*2009,**2099:**-18.Google Scholar

## Copyright

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.