activity
20232026
collaborators

13 papers

math.OA2026

Ground states on the \(\mathrm{C}^*\)-algebras of Fell bundles over étale groupoids

Md Amir Hossain

Let \(p\colon \mathcal{A}\to G\) be a Fell bundle over a locally compact Hausdorff second countable étale groupoid \(G\) and let \(\mathrm{C}^*(G; \mathcal{A})\) be the associated…

math.OA2026

Inclusions of Fell bundles -algebras and coaction crossed products

Md Amir Hossain

Let be a Fell bundle over a locally compact Hausdorff second countable groupoid equipped with a Haar system, and let be a discrete group. Given…

math.OA2026

On the Haagerup property for partial crossed products

Md Amir Hossain, Chaitanya J. Kulkarni

Let be a partial dynamical system and let denote the associated reduced partial crossed product. In this article, we introduce the Haagerup property fo…

math.OA2026

Some remarks on Reduced -algebras of semigroup dynamical systems and product systems

Md Amir Hossain, S. Sundar

We study the exactness of the reduced crossed product of a semigroup dynamical system and the reduced -algebra of a product system. We show that for a semigroup dynamical sy…

math.OA2025

Inductive limits of partial crossed products

Md Amir Hossain

Let be an inductive sequence of partial dynamical systems. We prove the existence of an induced partial action of …

math.OA2025

Extreme points of unital completely positive maps invariant under partial action

Chaitanya J. Kulkarni, Md Amir Hossain

The classical Choquet theorem establishes a barycentric decomposition for elements in a compact convex subset of a locally convex topological vector space. This decomposition is ac…

math.OA2025

Reduced -algebras of Product Systems -- an -semigroup and a Groupoid perspective

Md Amir Hossain, S. Sundar

For Ore semigroups with an order unit, we prove that there is a bijection between -semigroups over and product systems of -correspondences over . We exp…

math.OA2025

Metrics on -algebras of Étale groupoids from length functions

Arnab Chattopadhyay, Md Amir Hossain, Soumalya Joardar

We show that for an étale groupoid with compact unit space, the natural Dirac type operator from a continuous length function produces a natural pseudo-metric on the state space of…

math.OA2023

C-algebras of Fell bundles over étale groupoids

Rohit Dilip Holkar, Md Amir Hossain

We describe a construction for the full C-algebra of a possibly unsaturated Fell bundle over a possibly non-Hausdorff locally compact étale groupoid without appealing to Renaul…

math.OA2023

KMS states on the -algebras of Fell bundles over {é}tale groupoids

Rohit Dilip Holkar, Md Amir Hossain

Let be a saturated Fell bundle over a locally compact, Hausdorff, second countable, {é}tale groupoid~, and let denote i…

math.OA2023

Topological fundamental groupoid. III. Haar systems on the fundamental groupoid

Rohit Dilip Holkar, Md Amir Hossain

Let be a path connected, locally path connected and semilocally simply connected space; let be its universal cover. We discuss the existence and description of a Ha…

math.AT2023

Topological Fundamental Groupoid. II. An action category of the fundamental groupoid

Rohit Dilip Holkar, Md Amir Hossain, Dheeraj Kulkarni

For a path connected, locally path connected and semilocally simply connected space , let denote its topologised fundamental groupoid as established in the first articl…

math.AT2023

Topological fundamental groupoid. I

Rohit Dilip Holkar, Md Amir Hossain

We show that the fundamental groupoid~\(Π_1(X)\) of a locally path connected semilocally simply connected space~\(X\) can be equipped with a \emph{natural} topology so that it beco…