arXiv subjects

Alireza Medghalchi

Publications and source records attributed to Alireza Medghalchi.

6 recordsLinked to original sources

arXiv2003

Restricted algebras on inverse semigroups I, representation theory

The relation between representations and positive definite functions is a key concept in harmonic analysis on topological groups. Recently this relation has been studied on topological groupoids. This is the first in a series of papers in which we have investigated a similar relation on inverse semigroups. We use a new concept of "restricted" representations and study the restricted semigroup algebras and corresponding $C^*$-algebras.

math.OA↗

arXiv2003

Restricted algebras on inverse semigroups II, positive definite functions

The relation between representations and positive definite functions is a key concept in harmonic analysis on topological groups. Recently this relation has been studied on topological groupoids. This is the second in a series of papers in which we have investigated the concept of "restricted" positive definite functions and their relation with representations.

math.OA↗

arXiv2003

Restricted algebras on inverse semigroups III, Fourier algebra

The Fourier and Fourier-Stieltjes algebras $A(G)$ and $B(G)$ of a locally compact group $G$ are introduced and studied in 60's by Piere Eymard in his PhD thesis. If $G$ is a locally compact abelian group, then $A(G)\simeq L^1(\hat{G})$, and $B(G)\simeq M(\hat{G})$, via the Fourier and Fourier-Stieltjes transforms, where $\hat{G}$ is the Pontryagin dual of $G$. Recently these algebras are defined on a (topological or measured) groupoid and have shown to share many common features with the group case. This is the last in a series of papers in which we have investigated a "restricted" form of these algebras on a unital inverse semigroup $S$.

math.OA↗

arXiv2002

Fourier Algebras On Topological Foundation *-Semigroups

We introduce the notion of the Fourier and Fouier-Stieltjes algebra of a topological *-semigroup and show that these are commutative Banach algebras. For a class of foundation semigroups, we show that these are preduals of von Neumann algebras.

math.OA↗

arXiv2002

Amenability of the Algebras R(S), F(S) of a Topological Semigroup S

For a locally compact Hausdorff semigroup S, the $L^\infty$ representation algebra R(S) was extensively studied by Dunkl and Ramirez. The Fourier-Stieltjes algebra F(S) of a topological semigroup was studied by Lau. The aim of this paper is to investigate these two algebras and study the amenability of them with respect to the structure of S.

math.OA↗

arXiv2002

Harmonic Analysis on Double Coset Spaces

We prove the existance and uniqueness of quasi-invariant measure on double cost space $K\backslash G/H$ and study the Fourier and Fourier-Stieltjes algebras of these spaces.

math.FA↗