Research output: Contribution to Journal/Magazine › Journal article › peer-review
Uniform bounds for point cohomology of $\ell^1(\mathbb Z_+)$ and related algebras. / Choi, Yemon.
In: Journal of Mathematical Analysis and Applications, Vol. 358, No. 2, 15.10.2009, p. 249-260.Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Uniform bounds for point cohomology of $\ell^1(\mathbb Z_+)$ and related algebras
AU - Choi, Yemon
PY - 2009/10/15
Y1 - 2009/10/15
N2 - The point cohomology of the convolution algebra ℓ1(Z+) is known to vanish in degrees 2 and above. We sharpen this result by obtaining splitting maps whose norms are bounded independently of the choice of point module. Our construction is a by-product of new estimates on projectivity constants of maximal ideals in ℓ1(Z+). Analogous results are obtained for some other L1-algebras which arise from ‘rank one’ subsemigroups of R+.
AB - The point cohomology of the convolution algebra ℓ1(Z+) is known to vanish in degrees 2 and above. We sharpen this result by obtaining splitting maps whose norms are bounded independently of the choice of point module. Our construction is a by-product of new estimates on projectivity constants of maximal ideals in ℓ1(Z+). Analogous results are obtained for some other L1-algebras which arise from ‘rank one’ subsemigroups of R+.
KW - Point cohomology
KW - Semigroup algebra
KW - Uniformly bounded solution of cohomology problems
KW - Flat Banach module
KW - Maximal ideal
U2 - 10.1016/j.jmaa.2009.05.002
DO - 10.1016/j.jmaa.2009.05.002
M3 - Journal article
VL - 358
SP - 249
EP - 260
JO - Journal of Mathematical Analysis and Applications
JF - Journal of Mathematical Analysis and Applications
SN - 0022-247X
IS - 2
ER -