We revisit the old result that biflat Banach algebras have the same cyclic cohomology as C, and obtain a quantitative variant (which is needed in separate, joint work of the author on the simplicial and cyclic cohomology of band semigroup algebras). Our approach does not rely on the Connes-Tsygan exact sequence, but is motivated strongly by its construction as found in [2] and [5].
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-bc91-0-6, author = {Yemon Choi}, title = {Splitting maps and norm bounds for the cyclic cohomology of biflat Banach algebras}, journal = {Banach Center Publications}, volume = {89}, year = {2010}, pages = {105-121}, zbl = {1208.46070}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc91-0-6} }
Yemon Choi. Splitting maps and norm bounds for the cyclic cohomology of biflat Banach algebras. Banach Center Publications, Tome 89 (2010) pp. 105-121. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc91-0-6/