# Search results

Analysis Mathematica > 2019 > 45 > 3 > 461-473

*S*, we show that

*ℓ*

^{1}(

*S*) is not Johnson pseudo-contractible. Also for a Johnson pseudo-contractible Banach algebra

*A*, we show that

*A*has no non-zero complemented closed nilpotent ideal.

Positivity > 2019 > 23 > 5 > 1215-1224

Mediterranean Journal of Mathematics > 2019 > 16 > 1 > 1-13

Bollettino dell'Unione Matematica Italiana > 2019 > 12 > 4 > 517-524

*S*is amenable if and only if the semigroup algebra $$l^1(S)$$ ...

Russian Mathematics > 2018 > 62 > 2 > 62-68

*C**-algebra and obtain a compact quantum semigroup structure on this algebra. We show that the unique proper ideal of the Cuntz–Toeplitz algebra is not a co-ideal of the compact quantum semigroup. Thus, the compact quantum semigroup is a co-simple quantum semigroup.

Journal of Algebra > 2017 > 492 > C > 524-546

Semigroup Forum > 2018 > 96 > 2 > 348-356

*S*, the so-called archimedean semigroups. We show that for an archimedean semigroup

*S*, pseudo-amenability, amenability and approximate amenability of $$\ell ^1(S)$$ ℓ1(S) are equivalent. Then for a commutative semigroup

*S*, we show that pseudo-amenability...

Acta Mathematica Hungarica > 2016 > 150 > 2 > 512-523

*Y*is a subsemilattice of a finite semilattice indecomposable semigroup

*S*then $${|Y|\leq 2\left\lfloor \frac{|S|-1}{4} \right\rfloor+1}$$ | Y | ≤ 2 | S | - 1 4 + 1 . We also characterize finite semilattice indecomposable semigroups

*S*which contain a subsemilattice

*Y*with $${|S|=4k+1}$$ | S | = 4 k + 1 and $${|Y|=2\left\lfloor \frac{|S|-1}{4} \right\rfloor+1=2k+1}$$...

Journal of Algebra > 2016 > 452 > C > 196-211

Semigroup Forum > 2017 > 95 > 1 > 1-12

Algebras and Representation Theory > 2016 > 19 > 1 > 17-31

*K*[

*S*] of a submonoid

*S*of a finitely generated nilpotent group is studied via the spectra of the monoid

*S*and of the group algebra

*K*[

*G*] of the group

*G*of fractions of

*S*. It is shown that the classical Krull dimension of

*K*[

*S*] is equal to the Hirsch length of the group

*G*provided that

*G*is nilpotent of class two. This uses the fact that prime ideals of

*S*are...

Bulletin of the Malaysian Mathematical Sciences Society > 2016 > 39 > 3 > 993-1004

Acta Mathematica Hungarica > 2016 > 148 > 2 > 300-311

*S*, let $${{\mathbb F}[\varrho]}$$ F [ ϱ ] denote the ideal of the semigroup algebra $${{\mathbb F}[S]}$$ F [ S ] which determines the kernel of the...

Archiv der Mathematik > 2016 > 106 > 3 > 295-299

*G*is nilpotent of class two and its abelianisation is torsion-free and satisfies the ascending chain condition on cyclic subgroups. The result corrects and extends an earlier result by the authors to the case that

*G*is not necessarily finitely...

Journal of Algebra > 2015 > 440 > Complete > 72-99

Semigroup Forum > 2017 > 94 > 1 > 176-180

*S*with the set idempotents

*E*acting on

*S*trivially from left and by multiplication from right, any bounded module derivation from $$\ell ^1(S)$$ ℓ 1 ( S ) to $$({\ell ^1(S)}/{J})^*=J^{\perp }$$ ( ℓ 1 ( S ) / J ) ∗ = J ⊥ is inner, where

*J*is the closed ideal generated by elements of the form $$\delta _{set}-\delta _{st}$$...

Semigroup Forum > 2015 > 91 > 1 > 213-223

Functional Analysis and Its Applications > 2015 > 49 > 4 > 315-318

*A*-A-bimodule

*X*and every

*k*∈ N, the seminormed spaces

*H*

_{A}

^{ k }(

*A*,

*X**) and

*H*

^{ k }(

*A*/

*J,X**) are isomorphic, where

*J*is a specific closed ideal of

*A*. As an example, we show that, for an inverse...

Acta Mathematica Hungarica > 2014 > 144 > 2 > 407-415

*S*. We relate this to a new notion of amenability of Banach algebras modulo an ideal, to prove a version of Johnson’s theorem for a large class of semigroups, including inverse semigroups,

*E*-inversive...