If possible, give an example of a continuous function defined on a convex subset of a Banach space $X$ satisfies Kannan contraction but does not satisfy Banach contraction.
Contractions are always continuous and Kannan mappings are not necessarily continuous. Even more general condition in this paper: Górnicki, J. Fixed point theorems for Kannan type mappings. J. Fixed Point Theory Appl. 19, 2145–2152 (2017). https://doi.org/10.1007/s11784-017-0402-8 or here:
Fixed Point Theory and Applications Volume 2008, Article ID 649749, "Some Similarity between Contractions and Kannan Mappings" Misako Kikkawa, Tomonari Suzuki
Mieczyslaw Cichon Thank you for your consideration. I have gone through your suggested articles but unfortunately, I am sorry to say that I couldn't find any fruitful result supporting my question. If you can precisely mention a result(or, results) from those articles that will be very much helpful.
Please read the papers: section 12 in the first paper you have even more than Kannan contraction (new proposed FPT are presented) and some references ([7,8]) are directly referred to your question. If you expect ONLY a simple example, please use scholar.google.com . Please follow the papers by Gornicki or Wlodarczyk. Usually, people expect weaker conditions. If you wish: please check http://www.math.bas.bg/~serdica/2010/2010-001-010.pdf
Dear Friends, I am having one doubt about Kannan Mapping... Let T:X---> X be a Kannan Contraction Mapping and have fixed point x_0. It is possible to find a subset A of X containing x_0 so that the mapping T on A is the usual contraction?
I am having this doubt since any Kanan contraction mappings I have seen so far validate my question@.